code: def ltrim(self, key, start, stop):
          
          if not isinstance(start, int):
              raise TypeError("start argument must be int")
          if not isinstance(stop, int):
              raise TypeError("stop argument must be int")
          fut = self.execute(b'LTRIM', key, start, stop)
          return wait_ok(fut)
docs: Trim an existing list so that it will contain only the specified
          range of elements specified.
  
          :raises TypeError: if start or stop is not int