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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_output(process):
 """Stream the output of a process to stdout This function takes an existing process that will be polled for output. Only stdout will be polled and sent to sys.stdout. Args: process(subprocess.Popen):
 a process that has been started with stdout=PIPE and stderr=STDOUT Returns (int):
 process exit code """

    exit_code = None

    while exit_code is None:
        stdout = process.stdout.readline().decode("utf-8")
        sys.stdout.write(stdout)
        exit_code = process.poll()

    if exit_code != 0:
        raise RuntimeError("Process exited with code: %s" % exit_code)

    return exit_code