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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 stream(self, report, callback=None):
 """Stream a report asynchronously. If no one is listening for the report, the report may be dropped, otherwise it will be queued for sending Args: report (IOTileReport):
 The report that should be streamed callback (callable):
 Optional callback to get notified when this report is actually sent. """


        if self._push_channel is None:
            return

        self._push_channel.stream(report, callback=callback)