code: def psetex(self, key, milliseconds, value):
          
          return self._execute(
              [b'PSETEX', key, ascii(milliseconds), value], b'OK')
docs: :meth:`~tredis.RedisClient.psetex` works exactly like
          :meth:`~tredis.RedisClient.psetex` with the sole difference that the
          expire time is specified in milliseconds instead of seconds.
  
          .. versionadded:: 0.2.0
  
          .. note:: **Time complexity**: ``O(1)``
  
          :param key: The key to set
          :type key: :class:`str`, :class:`bytes`
          :param int milliseconds: Number of milliseconds for TTL
          :param value: The value to set
          :type value: :class:`str`, :class:`bytes`
          :rtype: bool
          :raises: :exc:`~tredis.exceptions.RedisError`