code: def lemmas(lemma,pos=None):
      
      lemma = lemma.lower()
      return [lemma_obj
          for synset in synsets(lemma,pos)
          for lemma_obj in synset.lemmas()
          if lemma_obj.name.lower() == lemma]
docs: Returns all the Lemma objects of which name is `lemma` and which have `pos` as part
      of speech.
  
      Parameters
      ----------
      lemma : str
        Literal of the sought Lemma objects.
      pos : str, optional
        Part of speech of the sought Lemma objects. If None, matches any part of speech.
        Defaults to None
        
      Returns
      -------
      list of Lemmas
        Lists all the matched Lemmas.