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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 wait_for_user(msg=""):
 """ Print MSG and a confirmation prompt. Waiting for user's confirmation, unless silent '--yes-i-know' command line option was used, in which case the function returns immediately without printing anything. """

    if '--yes-i-know' in sys.argv:
        return
    print(msg)
    try:
        answer = raw_input("Please confirm by typing 'Yes, I know!': ")
    except KeyboardInterrupt:
        print()
        answer = ''
    if answer != 'Yes, I know!':
        sys.stderr.write("ERROR: Aborted.\n")
        sys.exit(1)
    return