def METHOD_NAME(self, element_id=None, total=False):
    assert element_id is None
    mass_types = self._get_types(nlimit=True)
    element_id, i = self.get_indexs(element_id)
    if element_id is None:
        return None
    n = len(element_id)
    for mass_type in mass_types:
        element_id2 = union1d(element_id, mass_type.element_id)
        massi = mass_type.METHOD_NAME(element_id2, total)
    if total:
        mass = massi.sum()
    else:
        mass = massi
    return mass