def rels(self, rel_name = None):
if rel_name is not None:<EOL><INDENT>return [self._germanet.get_synset_by_id(mongo_id)<EOL>for (name, mongo_id) in self._rels if name == rel_name]<EOL><DEDENT>else:<EOL><INDENT>return [(name, self._germanet.get_synset_by_id(mongo_id))<EOL>for (name, mongo_id) in self._rels]<EOL><DEDENT>
Returns a list of lexical relations in this Synset.  If
`rel_name` is specified, returns a list of Synsets which are
reachable from this one by relations with the given name.  If
`rel_name` is not specified, returns a list of all the lexical
relations of this Synset, as tuples of (rel_name, synset).

Arguments:
- `rel_name`: