def ltrim(self, key, start, stop):
        """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
        """
        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)
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