diff --git a/test/implementations/caching/cache/QueueMapTest.cpp b/test/implementations/caching/cache/QueueMapTest.cpp
deleted file mode 100644
index 1ba2c368..00000000
--- a/test/implementations/caching/cache/QueueMapTest.cpp
+++ /dev/null
@@ -1,513 +0,0 @@
-#include <google/gtest/gtest.h>
-#include <messmer/cpp-utils/macros.h>
-#include "../../../../implementations/caching/cache/QueueMap.h"
-#include <memory>
-#include <boost/optional/optional_io.hpp>
-
-using ::testing::Test;
-using std::unique_ptr;
-using std::make_unique;
-
-using namespace blockstore::caching;
-
-// This is a not-default-constructible Key type
-class MinimalKeyType {
-public:
-  static int instances;
-  static MinimalKeyType create(int value) {
-    return MinimalKeyType(value);
-  }
-  bool operator==(const MinimalKeyType &rhs) const {
-    return _value == rhs._value;
-  }
-  int value() const {
-    return _value;
-  }
-  MinimalKeyType(const MinimalKeyType &rhs): MinimalKeyType(rhs.value()) {
-  }
-  ~MinimalKeyType() {
-    --instances;
-  }
-private:
-  MinimalKeyType(int value): _value(value) {
-    ++instances;
-  }
-  int _value;
-};
-int MinimalKeyType::instances = 0;
-namespace std {
-template <> struct hash<MinimalKeyType> {
-  size_t operator()(const MinimalKeyType &obj) const {
-    return obj.value();
-  }
-};
-}
-// This is a not-default-constructible non-copyable but moveable Value type
-class MinimalValueType {
-public:
-  static int instances;
-  static MinimalValueType create(int value) {
-    return MinimalValueType(value);
-  }
-  MinimalValueType(MinimalValueType &&rhs): MinimalValueType(rhs.value()) {
-    rhs._isMoved = true;
-  }
-  ~MinimalValueType() {
-    assert(!_isDestructed);
-    --instances;
-    _isDestructed = true;
-  }
-  int value() const {
-    assert(!_isMoved && !_isDestructed);
-    return _value;
-  }
-private:
-  MinimalValueType(int value): _value(value), _isMoved(false), _isDestructed(false) {
-    ++instances;
-  }
-  int _value;
-  bool _isMoved;
-  bool _isDestructed;
-  DISALLOW_COPY_AND_ASSIGN(MinimalValueType);
-};
-int MinimalValueType::instances = 0;
-
-class QueueMapTest: public Test {
-public:
-  QueueMapTest() {
-    MinimalKeyType::instances = 0;
-    MinimalValueType::instances = 0;
-    _map = make_unique<QueueMap<MinimalKeyType, MinimalValueType>>();
-  }
-  ~QueueMapTest() {
-    _map.reset();
-    EXPECT_EQ(0, MinimalKeyType::instances);
-    EXPECT_EQ(0, MinimalValueType::instances);
-  }
-  void push(int key, int value) {
-    _map->push(MinimalKeyType::create(key), MinimalValueType::create(value));
-  }
-  boost::optional<int> pop() {
-    auto elem = _map->pop();
-    if (!elem) {
-      return boost::none;
-    }
-    return elem.value().value();
-  }
-  boost::optional<int> pop(int key) {
-    auto elem = _map->pop(MinimalKeyType::create(key));
-    if (!elem) {
-      return boost::none;
-    }
-    return elem.value().value();
-  }
-  boost::optional<int> peek() {
-    auto elem = _map->peek();
-    if (!elem) {
-      return boost::none;
-    }
-    return elem.value().value();
-  }
-  int size() {
-    return _map->size();
-  }
-private:
-  unique_ptr<QueueMap<MinimalKeyType, MinimalValueType>> _map;
-};
-
-class QueueMapSizeTest: public QueueMapTest {};
-
-TEST_F(QueueMapSizeTest, Empty) {
-  EXPECT_EQ(0, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOne) {
-  push(2, 3);
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingTwo) {
-  push(2, 3);
-  push(3, 4);
-  EXPECT_EQ(2, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingTwoAndPoppingOldest) {
-  push(2, 3);
-  push(3, 4);
-  pop();
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingTwoAndPoppingFirst) {
-  push(2, 3);
-  push(3, 4);
-  pop(2);
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingTwoAndPoppingLast) {
-  push(2, 3);
-  push(3, 4);
-  pop(3);
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOne) {
-  push(2, 3);
-  pop();
-  EXPECT_EQ(0, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePerKey) {
-  push(2, 3);
-  pop(2);
-  EXPECT_EQ(0, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePushingOne) {
-  push(2, 3);
-  pop();
-  push(3, 4);
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePerKeyPushingOne) {
-  push(2, 3);
-  pop(2);
-  push(3, 4);
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePushingSame) {
-  push(2, 3);
-  pop();
-  push(2, 3);
-  EXPECT_EQ(1, size());
-}
-
-TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePerKeyPushingSame) {
-  push(2, 3);
-  pop(2);
-  push(2, 3);
-  EXPECT_EQ(1, size());
-}
-
-class QueueMapMemoryLeakTest: public QueueMapTest {
-public:
-  void EXPECT_NUM_INSTANCES(int num) {
-    EXPECT_EQ(num, MinimalKeyType::instances);
-    EXPECT_EQ(num, MinimalValueType::instances);
-  }
-};
-
-TEST_F(QueueMapMemoryLeakTest, Empty) {
-  EXPECT_NUM_INSTANCES(0);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOne) {
-  push(2, 3);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingTwo) {
-  push(2, 3);
-  push(3, 4);
-  EXPECT_NUM_INSTANCES(2);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingTwoAndPoppingOldest) {
-  push(2, 3);
-  push(3, 4);
-  pop();
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingTwoAndPoppingFirst) {
-  push(2, 3);
-  push(3, 4);
-  pop(2);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingTwoAndPoppingLast) {
-  push(2, 3);
-  push(3, 4);
-  pop(3);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOne) {
-  push(2, 3);
-  pop();
-  EXPECT_NUM_INSTANCES(0);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePerKey) {
-  push(2, 3);
-  pop(2);
-  EXPECT_NUM_INSTANCES(0);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePushingOne) {
-  push(2, 3);
-  pop();
-  push(3, 4);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePerKeyPushingOne) {
-  push(2, 3);
-  pop(2);
-  push(3, 4);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePushingSame) {
-  push(2, 3);
-  pop();
-  push(2, 3);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePerKeyPushingSame) {
-  push(2, 3);
-  pop(2);
-  push(2, 3);
-  EXPECT_NUM_INSTANCES(1);
-}
-
-class QueueMapValueTest: public QueueMapTest {};
-
-TEST_F(QueueMapValueTest, PoppingFromEmpty) {
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, PoppingFromEmptyPerKey) {
-  EXPECT_EQ(boost::none, pop(2));
-}
-
-TEST_F(QueueMapValueTest, PoppingNonexistingPerKey) {
-  push(3, 2);
-  EXPECT_EQ(boost::none, pop(2));
-}
-
-TEST_F(QueueMapValueTest, PushingOne) {
-  push(3, 2);
-  EXPECT_EQ(2, pop(3).value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, PushingTwo) {
-  push(2, 3);
-  push(3, 4);
-  EXPECT_EQ(3, pop().value());
-  EXPECT_EQ(4, pop().value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, AfterPushingTwoAndPoppingFirst) {
-  push(2, 3);
-  push(3, 4);
-  pop(2);
-  EXPECT_EQ(boost::none, pop(2));
-  EXPECT_EQ(4, pop(3).value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, AfterPushingTwoAndPoppingLast) {
-  push(2, 3);
-  push(3, 4);
-  pop(3);
-  EXPECT_EQ(boost::none, pop(3));
-  EXPECT_EQ(3, pop(2).value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, AfterPushingOnePoppingOne) {
-  push(2, 3);
-  pop();
-  EXPECT_EQ(boost::none, pop());
-  EXPECT_EQ(boost::none, pop(2));
-}
-
-TEST_F(QueueMapValueTest, AfterPushingOnePoppingOnePerKey) {
-  push(2, 3);
-  pop(2);
-  EXPECT_EQ(boost::none, pop());
-  EXPECT_EQ(boost::none, pop(2));
-}
-
-TEST_F(QueueMapValueTest, AfterPushingOnePoppingOnePushingOne) {
-  push(2, 3);
-  pop();
-  push(3, 4);
-  EXPECT_EQ(boost::none, pop(2));
-  EXPECT_EQ(4, pop(3).value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, AfterPushingOnePoppingOnePerKeyPushingOne) {
-  push(2, 3);
-  pop(2);
-  push(3, 4);
-  EXPECT_EQ(boost::none, pop(2));
-  EXPECT_EQ(4, pop(3).value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, PushingSomePoppingMiddlePerKey) {
-  push(1, 2);
-  push(2, 3);
-  push(3, 4);
-  push(4, 5);
-  push(5, 6);
-  EXPECT_EQ(3, pop(2).value());
-  EXPECT_EQ(5, pop(4).value());
-  EXPECT_EQ(2, pop().value());
-  EXPECT_EQ(4, pop().value());
-  EXPECT_EQ(6, pop().value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, PushingSomePoppingFirstPerKey) {
-  push(1, 2);
-  push(2, 3);
-  push(3, 4);
-  push(4, 5);
-  push(5, 6);
-  EXPECT_EQ(2, pop(1).value());
-  EXPECT_EQ(3, pop(2).value());
-  EXPECT_EQ(4, pop().value());
-  EXPECT_EQ(5, pop().value());
-  EXPECT_EQ(6, pop().value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapValueTest, PushingSomePoppingLastPerKey) {
-  push(1, 2);
-  push(2, 3);
-  push(3, 4);
-  push(4, 5);
-  push(5, 6);
-  EXPECT_EQ(6, pop(5).value());
-  EXPECT_EQ(5, pop(4).value());
-  EXPECT_EQ(2, pop().value());
-  EXPECT_EQ(3, pop().value());
-  EXPECT_EQ(4, pop().value());
-  EXPECT_EQ(boost::none, pop());
-}
-
-//This test forces the underlying datastructure (std::map or std::unordered_map) to grow and reallocate memory.
-//So it tests, that QueueMap still works after reallocating memory.
-TEST_F(QueueMapValueTest, ManyValues) {
-  //Push 1 million entries
-  for (int i = 0; i < 1000000; ++i) {
-    push(i, 2*i);
-  }
-  //pop every other one by key
-  for (int i = 0; i < 1000000; i += 2) {
-    EXPECT_EQ(2*i, pop(i).value());
-  }
-  //pop the rest in queue order
-  for (int i = 1; i < 1000000; i += 2) {
-    EXPECT_EQ(2*i, peek().value());
-    EXPECT_EQ(2*i, pop().value());
-  }
-  EXPECT_EQ(0, size());
-  EXPECT_EQ(boost::none, pop());
-  EXPECT_EQ(boost::none, peek());
-}
-
-TEST_F(QueueMapValueTest, PushAlreadyExistingValue) {
-  push(2, 3);
-  EXPECT_ANY_THROW(
-    push(2, 4);
-  );
-}
-
-class QueueMapPeekTest: public QueueMapTest {};
-
-TEST_F(QueueMapPeekTest, PoppingFromEmpty) {
-  EXPECT_EQ(boost::none, peek());
-}
-
-TEST_F(QueueMapPeekTest, PushingOne) {
-  push(3, 2);
-  EXPECT_EQ(2, peek().value());
-}
-
-TEST_F(QueueMapPeekTest, PushingTwo) {
-  push(2, 3);
-  push(3, 4);
-  EXPECT_EQ(3, peek().value());
-  EXPECT_EQ(3, peek().value());
-  EXPECT_EQ(3, pop().value());
-  EXPECT_EQ(4, peek().value());
-  EXPECT_EQ(4, peek().value());
-  EXPECT_EQ(4, pop().value());
-  EXPECT_EQ(boost::none, peek());
-  EXPECT_EQ(boost::none, pop());
-}
-
-TEST_F(QueueMapPeekTest, AfterPushingTwoAndPoppingFirst) {
-  push(2, 3);
-  push(3, 4);
-  pop(2);
-  EXPECT_EQ(boost::none, pop(2));
-  EXPECT_EQ(4, peek().value());
-}
-
-class CopyableValueType {
-public:
-  static int numCopyConstructorCalled;
-  CopyableValueType(int value): _value(value) {}
-  CopyableValueType(const CopyableValueType &rhs): CopyableValueType(rhs._value) {
-    ++numCopyConstructorCalled;
-  }
-  CopyableValueType(CopyableValueType &&rhs): CopyableValueType(rhs._value) {
-    //Don't increase numCopyConstructorCalled
-  }
-  int value() const {
-    return _value;
-  }
-private:
-  int _value;
-};
-int CopyableValueType::numCopyConstructorCalled = 0;
-
-//Test that QueueMap uses a move constructor for Value if possible
-class QueueMapMoveConstructorTest: public Test {
-public:
-  QueueMapMoveConstructorTest() {
-    CopyableValueType::numCopyConstructorCalled = 0;
-    map = make_unique<QueueMap<MinimalKeyType, CopyableValueType>>();
-  }
-  unique_ptr<QueueMap<MinimalKeyType, CopyableValueType>> map;
-};
-
-TEST_F(QueueMapMoveConstructorTest, PushingAndPopping_MoveIntoMap) {
-  map->push(MinimalKeyType::create(0), CopyableValueType(2));
-  CopyableValueType val = map->pop().value();
-  EXPECT_EQ(0, CopyableValueType::numCopyConstructorCalled);
-}
-
-TEST_F(QueueMapMoveConstructorTest, PushingAndPoppingPerKey_MoveIntoMap) {
-  map->push(MinimalKeyType::create(0), CopyableValueType(2));
-  CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
-  EXPECT_EQ(0, CopyableValueType::numCopyConstructorCalled);
-}
-
-TEST_F(QueueMapMoveConstructorTest, PushingAndPopping_CopyIntoMap) {
-  CopyableValueType value(2);
-  map->push(MinimalKeyType::create(0), value);
-  CopyableValueType val = map->pop().value();
-  EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
-}
-
-TEST_F(QueueMapMoveConstructorTest, PushingAndPoppingPerKey_CopyIntoMap) {
-  CopyableValueType value(2);
-  map->push(MinimalKeyType::create(0), value);
-  CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
-  EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
-}
diff --git a/test/implementations/caching/cache/QueueMapTest_MemoryLeak.cpp b/test/implementations/caching/cache/QueueMapTest_MemoryLeak.cpp
new file mode 100644
index 00000000..74012fc0
--- /dev/null
+++ b/test/implementations/caching/cache/QueueMapTest_MemoryLeak.cpp
@@ -0,0 +1,87 @@
+#include "testutils/QueueMapTest.h"
+
+// Tests that QueueMap calls destructors correctly.
+// This is needed, because QueueMap does its own memory management.
+class QueueMapTest_MemoryLeak: public QueueMapTest {
+public:
+  void EXPECT_NUM_INSTANCES(int num) {
+    EXPECT_EQ(num, MinimalKeyType::instances);
+    EXPECT_EQ(num, MinimalValueType::instances);
+  }
+};
+
+TEST_F(QueueMapTest_MemoryLeak, Empty) {
+  EXPECT_NUM_INSTANCES(0);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOne) {
+  push(2, 3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_NUM_INSTANCES(2);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingTwoAndPoppingOldest) {
+  push(2, 3);
+  push(3, 4);
+  pop();
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingTwoAndPoppingLast) {
+  push(2, 3);
+  push(3, 4);
+  pop(3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOnePoppingOne) {
+  push(2, 3);
+  pop();
+  EXPECT_NUM_INSTANCES(0);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOnePoppingOnePerKey) {
+  push(2, 3);
+  pop(2);
+  EXPECT_NUM_INSTANCES(0);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOnePoppingOnePushingOne) {
+  push(2, 3);
+  pop();
+  push(3, 4);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOnePoppingOnePerKeyPushingOne) {
+  push(2, 3);
+  pop(2);
+  push(3, 4);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOnePoppingOnePushingSame) {
+  push(2, 3);
+  pop();
+  push(2, 3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapTest_MemoryLeak, AfterPushingOnePoppingOnePerKeyPushingSame) {
+  push(2, 3);
+  pop(2);
+  push(2, 3);
+  EXPECT_NUM_INSTANCES(1);
+}
diff --git a/test/implementations/caching/cache/QueueMapTest_MoveConstructor.cpp b/test/implementations/caching/cache/QueueMapTest_MoveConstructor.cpp
new file mode 100644
index 00000000..e762f3d0
--- /dev/null
+++ b/test/implementations/caching/cache/QueueMapTest_MoveConstructor.cpp
@@ -0,0 +1,64 @@
+#include <google/gtest/gtest.h>
+#include <memory>
+#include "../../../../implementations/caching/cache/QueueMap.h"
+#include "testutils/MinimalKeyType.h"
+
+using namespace blockstore::caching;
+
+using ::testing::Test;
+using std::unique_ptr;
+using std::make_unique;
+
+class CopyableValueType {
+public:
+  static int numCopyConstructorCalled;
+  CopyableValueType(int value): _value(value) {}
+  CopyableValueType(const CopyableValueType &rhs): CopyableValueType(rhs._value) {
+    ++numCopyConstructorCalled;
+  }
+  CopyableValueType(CopyableValueType &&rhs): CopyableValueType(rhs._value) {
+    //Don't increase numCopyConstructorCalled
+  }
+  int value() const {
+    return _value;
+  }
+private:
+  int _value;
+};
+int CopyableValueType::numCopyConstructorCalled = 0;
+
+//Test that QueueMap uses a move constructor for Value if possible
+class QueueMapTest_MoveConstructor: public Test {
+public:
+  QueueMapTest_MoveConstructor() {
+    CopyableValueType::numCopyConstructorCalled = 0;
+    map = make_unique<QueueMap<MinimalKeyType, CopyableValueType>>();
+  }
+  unique_ptr<QueueMap<MinimalKeyType, CopyableValueType>> map;
+};
+
+TEST_F(QueueMapTest_MoveConstructor, PushingAndPopping_MoveIntoMap) {
+  map->push(MinimalKeyType::create(0), CopyableValueType(2));
+  CopyableValueType val = map->pop().value();
+  EXPECT_EQ(0, CopyableValueType::numCopyConstructorCalled);
+}
+
+TEST_F(QueueMapTest_MoveConstructor, PushingAndPoppingPerKey_MoveIntoMap) {
+  map->push(MinimalKeyType::create(0), CopyableValueType(2));
+  CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
+  EXPECT_EQ(0, CopyableValueType::numCopyConstructorCalled);
+}
+
+TEST_F(QueueMapTest_MoveConstructor, PushingAndPopping_CopyIntoMap) {
+  CopyableValueType value(2);
+  map->push(MinimalKeyType::create(0), value);
+  CopyableValueType val = map->pop().value();
+  EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
+}
+
+TEST_F(QueueMapTest_MoveConstructor, PushingAndPoppingPerKey_CopyIntoMap) {
+  CopyableValueType value(2);
+  map->push(MinimalKeyType::create(0), value);
+  CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
+  EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
+}
diff --git a/test/implementations/caching/cache/QueueMapTest_Peek.cpp b/test/implementations/caching/cache/QueueMapTest_Peek.cpp
new file mode 100644
index 00000000..ba3c7ead
--- /dev/null
+++ b/test/implementations/caching/cache/QueueMapTest_Peek.cpp
@@ -0,0 +1,34 @@
+#include "testutils/QueueMapTest.h"
+#include <boost/optional/optional_io.hpp>
+
+class QueueMapPeekTest: public QueueMapTest {};
+
+TEST_F(QueueMapPeekTest, PoppingFromEmpty) {
+  EXPECT_EQ(boost::none, peek());
+}
+
+TEST_F(QueueMapPeekTest, PushingOne) {
+  push(3, 2);
+  EXPECT_EQ(2, peek().value());
+}
+
+TEST_F(QueueMapPeekTest, PushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_EQ(3, peek().value());
+  EXPECT_EQ(3, peek().value());
+  EXPECT_EQ(3, pop().value());
+  EXPECT_EQ(4, peek().value());
+  EXPECT_EQ(4, peek().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(boost::none, peek());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapPeekTest, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, peek().value());
+}
diff --git a/test/implementations/caching/cache/QueueMapTest_Size.cpp b/test/implementations/caching/cache/QueueMapTest_Size.cpp
new file mode 100644
index 00000000..e4d72c9d
--- /dev/null
+++ b/test/implementations/caching/cache/QueueMapTest_Size.cpp
@@ -0,0 +1,79 @@
+#include "testutils/QueueMapTest.h"
+
+class QueueMapTest_Size: public QueueMapTest {};
+
+TEST_F(QueueMapTest_Size, Empty) {
+  EXPECT_EQ(0, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOne) {
+  push(2, 3);
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_EQ(2, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingTwoAndPoppingOldest) {
+  push(2, 3);
+  push(3, 4);
+  pop();
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingTwoAndPoppingLast) {
+  push(2, 3);
+  push(3, 4);
+  pop(3);
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOnePoppingOne) {
+  push(2, 3);
+  pop();
+  EXPECT_EQ(0, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOnePoppingOnePerKey) {
+  push(2, 3);
+  pop(2);
+  EXPECT_EQ(0, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOnePoppingOnePushingOne) {
+  push(2, 3);
+  pop();
+  push(3, 4);
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOnePoppingOnePerKeyPushingOne) {
+  push(2, 3);
+  pop(2);
+  push(3, 4);
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOnePoppingOnePushingSame) {
+  push(2, 3);
+  pop();
+  push(2, 3);
+  EXPECT_EQ(1, size());
+}
+
+TEST_F(QueueMapTest_Size, AfterPushingOnePoppingOnePerKeyPushingSame) {
+  push(2, 3);
+  pop(2);
+  push(2, 3);
+  EXPECT_EQ(1, size());
+}
diff --git a/test/implementations/caching/cache/QueueMapTest_Values.cpp b/test/implementations/caching/cache/QueueMapTest_Values.cpp
new file mode 100644
index 00000000..1acd5069
--- /dev/null
+++ b/test/implementations/caching/cache/QueueMapTest_Values.cpp
@@ -0,0 +1,150 @@
+#include "testutils/QueueMapTest.h"
+
+class QueueMapTest_Values: public QueueMapTest {};
+
+TEST_F(QueueMapTest_Values, PoppingFromEmpty) {
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, PoppingFromEmptyPerKey) {
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapTest_Values, PoppingNonexistingPerKey) {
+  push(3, 2);
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapTest_Values, PushingOne) {
+  push(3, 2);
+  EXPECT_EQ(2, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, PushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_EQ(3, pop().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, AfterPushingTwoAndPoppingLast) {
+  push(2, 3);
+  push(3, 4);
+  pop(3);
+  EXPECT_EQ(boost::none, pop(3));
+  EXPECT_EQ(3, pop(2).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, AfterPushingOnePoppingOne) {
+  push(2, 3);
+  pop();
+  EXPECT_EQ(boost::none, pop());
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapTest_Values, AfterPushingOnePoppingOnePerKey) {
+  push(2, 3);
+  pop(2);
+  EXPECT_EQ(boost::none, pop());
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapTest_Values, AfterPushingOnePoppingOnePushingOne) {
+  push(2, 3);
+  pop();
+  push(3, 4);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, AfterPushingOnePoppingOnePerKeyPushingOne) {
+  push(2, 3);
+  pop(2);
+  push(3, 4);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, PushingSomePoppingMiddlePerKey) {
+  push(1, 2);
+  push(2, 3);
+  push(3, 4);
+  push(4, 5);
+  push(5, 6);
+  EXPECT_EQ(3, pop(2).value());
+  EXPECT_EQ(5, pop(4).value());
+  EXPECT_EQ(2, pop().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(6, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, PushingSomePoppingFirstPerKey) {
+  push(1, 2);
+  push(2, 3);
+  push(3, 4);
+  push(4, 5);
+  push(5, 6);
+  EXPECT_EQ(2, pop(1).value());
+  EXPECT_EQ(3, pop(2).value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(5, pop().value());
+  EXPECT_EQ(6, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapTest_Values, PushingSomePoppingLastPerKey) {
+  push(1, 2);
+  push(2, 3);
+  push(3, 4);
+  push(4, 5);
+  push(5, 6);
+  EXPECT_EQ(6, pop(5).value());
+  EXPECT_EQ(5, pop(4).value());
+  EXPECT_EQ(2, pop().value());
+  EXPECT_EQ(3, pop().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+//This test forces the underlying datastructure (std::map or std::unordered_map) to grow and reallocate memory.
+//So it tests, that QueueMap still works after reallocating memory.
+TEST_F(QueueMapTest_Values, ManyValues) {
+  //Push 1 million entries
+  for (int i = 0; i < 1000000; ++i) {
+    push(i, 2*i);
+  }
+  //pop every other one by key
+  for (int i = 0; i < 1000000; i += 2) {
+    EXPECT_EQ(2*i, pop(i).value());
+  }
+  //pop the rest in queue order
+  for (int i = 1; i < 1000000; i += 2) {
+    EXPECT_EQ(2*i, peek().value());
+    EXPECT_EQ(2*i, pop().value());
+  }
+  EXPECT_EQ(0, size());
+  EXPECT_EQ(boost::none, pop());
+  EXPECT_EQ(boost::none, peek());
+}
+
+TEST_F(QueueMapTest_Values, PushAlreadyExistingValue) {
+  push(2, 3);
+  EXPECT_ANY_THROW(
+    push(2, 4);
+  );
+}
diff --git a/test/implementations/caching/cache/testutils/MinimalKeyType.cpp b/test/implementations/caching/cache/testutils/MinimalKeyType.cpp
new file mode 100644
index 00000000..f6b327ff
--- /dev/null
+++ b/test/implementations/caching/cache/testutils/MinimalKeyType.cpp
@@ -0,0 +1,3 @@
+#include "MinimalKeyType.h"
+
+int MinimalKeyType::instances = 0;
diff --git a/test/implementations/caching/cache/testutils/MinimalKeyType.h b/test/implementations/caching/cache/testutils/MinimalKeyType.h
new file mode 100644
index 00000000..9133d1f8
--- /dev/null
+++ b/test/implementations/caching/cache/testutils/MinimalKeyType.h
@@ -0,0 +1,47 @@
+#pragma once
+#ifndef BLOCKS_MESSMER_BLOCKSTORE_TEST_IMPLEMENTATIONS_CACHING_CACHE_TESTUTILS_MINIMALKEYTYPE_H_
+#define BLOCKS_MESSMER_BLOCKSTORE_TEST_IMPLEMENTATIONS_CACHING_CACHE_TESTUTILS_MINIMALKEYTYPE_H_
+
+#include <unordered_map>
+
+// This is a not-default-constructible Key type
+class MinimalKeyType {
+public:
+  static int instances;
+
+  static MinimalKeyType create(int value) {
+    return MinimalKeyType(value);
+  }
+
+  MinimalKeyType(const MinimalKeyType &rhs): MinimalKeyType(rhs.value()) {
+  }
+
+  ~MinimalKeyType() {
+    --instances;
+  }
+
+  int value() const {
+    return _value;
+  }
+
+private:
+  MinimalKeyType(int value): _value(value) {
+    ++instances;
+  }
+
+  int _value;
+};
+
+namespace std {
+template <> struct hash<MinimalKeyType> {
+  size_t operator()(const MinimalKeyType &obj) const {
+    return obj.value();
+  }
+};
+}
+
+inline bool operator==(const MinimalKeyType &lhs, const MinimalKeyType &rhs) {
+  return lhs.value() == rhs.value();
+}
+
+#endif
diff --git a/test/implementations/caching/cache/testutils/MinimalValueType.cpp b/test/implementations/caching/cache/testutils/MinimalValueType.cpp
new file mode 100644
index 00000000..f5cbdbae
--- /dev/null
+++ b/test/implementations/caching/cache/testutils/MinimalValueType.cpp
@@ -0,0 +1,3 @@
+#include "MinimalValueType.h"
+
+int MinimalValueType::instances = 0;
diff --git a/test/implementations/caching/cache/testutils/MinimalValueType.h b/test/implementations/caching/cache/testutils/MinimalValueType.h
new file mode 100644
index 00000000..9e48e43e
--- /dev/null
+++ b/test/implementations/caching/cache/testutils/MinimalValueType.h
@@ -0,0 +1,44 @@
+#pragma once
+#ifndef BLOCKS_MESSMER_BLOCKSTORE_TEST_IMPLEMENTATIONS_CACHING_CACHE_TESTUTILS_MINIMALVALUETYPE_H_
+#define BLOCKS_MESSMER_BLOCKSTORE_TEST_IMPLEMENTATIONS_CACHING_CACHE_TESTUTILS_MINIMALVALUETYPE_H_
+
+#include <messmer/cpp-utils/macros.h>
+#include <cassert>
+
+// This is a not-default-constructible non-copyable but moveable Value type
+class MinimalValueType {
+public:
+  static int instances;
+
+  static MinimalValueType create(int value) {
+    return MinimalValueType(value);
+  }
+
+  MinimalValueType(MinimalValueType &&rhs): MinimalValueType(rhs.value()) {
+    rhs._isMoved = true;
+  }
+
+  ~MinimalValueType() {
+    assert(!_isDestructed);
+    --instances;
+    _isDestructed = true;
+  }
+
+  int value() const {
+    assert(!_isMoved && !_isDestructed);
+    return _value;
+  }
+
+private:
+  MinimalValueType(int value): _value(value), _isMoved(false), _isDestructed(false) {
+    ++instances;
+  }
+
+  int _value;
+  bool _isMoved;
+  bool _isDestructed;
+
+  DISALLOW_COPY_AND_ASSIGN(MinimalValueType);
+};
+
+#endif
diff --git a/test/implementations/caching/cache/testutils/QueueMapTest.cpp b/test/implementations/caching/cache/testutils/QueueMapTest.cpp
new file mode 100644
index 00000000..f61b41a3
--- /dev/null
+++ b/test/implementations/caching/cache/testutils/QueueMapTest.cpp
@@ -0,0 +1,45 @@
+#include "QueueMapTest.h"
+
+QueueMapTest::QueueMapTest() {
+  MinimalKeyType::instances = 0;
+  MinimalValueType::instances = 0;
+  _map = std::make_unique<blockstore::caching::QueueMap<MinimalKeyType, MinimalValueType>>();
+}
+
+QueueMapTest::~QueueMapTest() {
+  _map.reset();
+  EXPECT_EQ(0, MinimalKeyType::instances);
+  EXPECT_EQ(0, MinimalValueType::instances);
+}
+
+void QueueMapTest::push(int key, int value) {
+  _map->push(MinimalKeyType::create(key), MinimalValueType::create(value));
+}
+
+boost::optional<int> QueueMapTest::pop() {
+  auto elem = _map->pop();
+  if (!elem) {
+    return boost::none;
+  }
+  return elem.value().value();
+}
+
+boost::optional<int> QueueMapTest::pop(int key) {
+  auto elem = _map->pop(MinimalKeyType::create(key));
+  if (!elem) {
+    return boost::none;
+  }
+  return elem.value().value();
+}
+
+boost::optional<int> QueueMapTest::peek() {
+  auto elem = _map->peek();
+  if (!elem) {
+    return boost::none;
+  }
+  return elem.value().value();
+}
+
+int QueueMapTest::size() {
+  return _map->size();
+}
diff --git a/test/implementations/caching/cache/testutils/QueueMapTest.h b/test/implementations/caching/cache/testutils/QueueMapTest.h
new file mode 100644
index 00000000..e49ad93f
--- /dev/null
+++ b/test/implementations/caching/cache/testutils/QueueMapTest.h
@@ -0,0 +1,32 @@
+#pragma once
+#ifndef BLOCKS_MESSMER_BLOCKSTORE_TEST_IMPLEMENTATIONS_CACHING_CACHE_TESTUTILS_QUEUEMAPTEST_H_
+#define BLOCKS_MESSMER_BLOCKSTORE_TEST_IMPLEMENTATIONS_CACHING_CACHE_TESTUTILS_QUEUEMAPTEST_H_
+
+#include <google/gtest/gtest.h>
+#include <memory>
+#include "../../../../../implementations/caching/cache/QueueMap.h"
+#include "MinimalKeyType.h"
+#include "MinimalValueType.h"
+#include <boost/optional.hpp>
+
+// This class is a parent class for tests on QueueMap.
+// It offers functions to work with a QueueMap test object which is built using types having only the minimal type requirements.
+// Furthermore, the class checks that there are no memory leaks left after destructing the QueueMap (by counting leftover instances of Keys/Values).
+class QueueMapTest: public ::testing::Test {
+public:
+  QueueMapTest();
+  ~QueueMapTest();
+
+  void push(int key, int value);
+  boost::optional<int> pop();
+  boost::optional<int> pop(int key);
+  boost::optional<int> peek();
+  int size();
+
+private:
+  std::unique_ptr<blockstore::caching::QueueMap<MinimalKeyType, MinimalValueType>> _map;
+};
+
+
+
+#endif