from abc import ABC, abstractmethod class _Methods(ABC): """Abstract Base Class for all methods.""" @abstractmethod def q(self): pass @abstractmethod def u(self): pass @abstractmethod def bodies(self): pass @abstractmethod def loads(self): pass @abstractmethod def mass_matrix(self): pass @abstractmethod def forcing(self): pass @abstractmethod def mass_matrix_full(self): pass @abstractmethod def forcing_full(self): pass def _form_eoms(self): raise NotImplementedError("Subclasses must implement this.")