<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def extend(self, iterable):
 """Extend the right side of this GeventDeque by appending elements from the iterable argument. """

        self._deque.extend(iterable)
        if len(self._deque) > 0:
            self.notEmpty.set()