def METHOD_NAME(self, t):
    """
    The degree of the basis element indexed by the partition ``t``
    in this filtered module.
    INPUT:
    - ``t`` -- the index of an element of the basis of this module,
      i.e. a partition
    OUTPUT: an integer, the degree of the corresponding basis element
    EXAMPLES::
        sage: # needs sage.modules
        sage: A = ModulesWithBasis(QQ).Filtered().example()
        sage: A.degree_on_basis(Partition((2,1)))
        3
        sage: A.degree_on_basis(Partition((4,2,1,1,1,1)))
        10
        sage: type(A.degree_on_basis(Partition((1,1))))
        <class 'sage.rings.integer.Integer'>
    """
    return t.size()