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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_stdin(self):
 """ Received data on stdin. Read and send to server. """

        with nonblocking(sys.stdin.fileno()):
            data = self._stdin_reader.read()

        # Send input in chunks of 4k.
        step = 4056
        for i in range(0, len(data), step):
            self._send_packet({
                'cmd': 'in',
                'data': data[i:i + step],
            })