code: def lemmas(self, lemma, pos = None):
          '''
          Looks up lemmas in the GermaNet database.
  
          Arguments:
          - `lemma`:
          - `pos`:
          '''
          if pos is not None:
              if pos not in SHORT_POS_TO_LONG:
                  return None
              pos         = SHORT_POS_TO_LONG[pos]
              lemma_dicts = self._mongo_db.lexunits.find({'orthForm': lemma,
                                                          'category': pos})
          else:
              lemma_dicts = self._mongo_db.lexunits.find({'orthForm': lemma})
          return sorted([Lemma(self, lemma_dict) for lemma_dict in lemma_dicts]f lemmas(self, lemma, pos = None):
          '''
          Looks up lemmas in the GermaNet database.
  
          Arguments:
          - `lemma`:
          - `pos`:
          '''
          if pos is not None:
              if pos not in SHORT_POS_TO_LONG:
                  return None
              pos         = SHORT_POS_TO_LONG[pos]
              lemma_dicts = self._mongo_db.lexunits.find({'orthForm': lemma,
                                                          'category': pos})
          else:
              lemma_dicts = self._mongo_db.lexunits.find({'orthForm': lemma})
          return sorted([Lemma(self, lemma_dict) for lemma_dict in lemma_dicts])
docs: Looks up lemmas in the GermaNet database.
  
          Arguments:
          - `lemma`:
          - `pos`: