def METHOD_NAME(
    self,
) -> Callable[[list | np.ndarray, float, list[float] | None], bool] | None:
    """Returns a default filter criterion method to filter the eigenvalues computed by the
    eigen solver. For more information see also
    qiskit.algorithms.eigen_solvers.NumPyEigensolver.filter_criterion.
    In the fermionic case the default filter ensures that the number of particles is being
    preserved.
    """
    return None