docs: def idict(self, in_dict={}):
          """Return a dict that uses this server's IRC casemapping.
  
          All keys in this dictionary are stored and compared using this server's casemapping.
          """
          new_dict = IDict(in_dict)
          new_dict.set_std(self.features.get('casemapping'))
          if not self._casemap_set:
              self._imaps.append(new_dict)
          return new_dict