code: def listIds(self, exclude=list()):
          
          lst = list(self.aliasesToIds.keys())
          others = set(self.idsToSigners.keys()) - \
              set(self.aliasesToIds.values())
          lst.extend(list(others))
          for x in exclude:
              lst.remove(x)
          return lst
docs: For each signer in this wallet, return its alias if present else
          return its identifier.
  
          :param exclude:
          :return: List of identifiers/aliases.