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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 join(self, timeout=None):
 """Join managed ioloop thread, or do nothing if not managed."""

        if not self._ioloop_managed:
            # Do nothing if the loop is not managed
            return
        try:
            self._ioloop_thread.join(timeout)
        except AttributeError:
            raise RuntimeError('Cannot join if not started')