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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 _process_callbacks(self):
 """ Process callbacks from `call_from_executor` in eventloop. """

        # Flush all the pipe content.
        os.read(self._schedule_pipe[0], 1024)

        # Process calls from executor.
        calls_from_executor, self._calls_from_executor = self._calls_from_executor, []
        for c in calls_from_executor:
            c()