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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def put(self, obj=None):
 """ Enqueue an object, waking the first thread waiting for a result, if one exists. :param obj: Object to enqueue. Defaults to :data:`None` as a convenience when using :class:`Latch` only for synchronization. :raises mitogen.core.LatchError: :meth:`close` has been called, and the object is no longer valid. """

        _vv and IOLOG.debug('%r.put(%r)', self, obj)
        self._lock.acquire()
        try:
            if self.closed:
                raise LatchError()
            self._queue.append(obj)

            if self._waking < len(self._sleeping):
                wsock, cookie = self._sleeping[self._waking]
                self._waking += 1
                _vv and IOLOG.debug('%r.put() -> waking wfd=%r',
                                    self, wsock.fileno())
                self._wake(wsock, cookie)
            elif self.notify:
                self.notify(self)
        finally:
            self._lock.release()