def union(self, *args):
        """Unions the equivalence classes containing the elements in `*args`."""
        if self._readonly:
            raise AttributeError

        if len(args) == 0:
            return None
        if len(args) == 1:
            return self[args[0]]
        for a, b in zip(args[:-1], args[1:]):
            result = self._union_pair(a, b)
        return result
def union ( self , * args ) : if self . _readonly : raise AttributeError if len ( args ) == 0 : return None if len ( args ) == 1 : return self [ args [ 0 ] ] for a , b in zip ( args [ : - 1 ] , args [ 1 : ] ) : result = self . _union_pair ( a , b ) return result
Unions the equivalence classes containing the elements in `*args`.