Check that all ligands (specified via the set or list all_domain_residue_ids containing columns 21:27 of the
           HETATM records) in the source PDB file are considered in the mapping.

def is_complete(self, all_domain_residue_ids):
        '''Check that all ligands (specified via the set or list all_domain_residue_ids containing columns 21:27 of the
           HETATM records) in the source PDB file are considered in the mapping.'''
        mapped_domain_residues = sorted([v.from_pdb_residue_id for k, v in self.mapping.iteritems()])
        assert(len(all_domain_residue_ids) == len(set(all_domain_residue_ids)))
        return mapped_domain_residues == sorted(all_domain_residue_ids)