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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 verify(ctx, file, account):
 """ Verify a signed message """

    if not file:
        print_message("Prompting for message. Terminate with CTRL-D", "info")
        file = click.get_text_stream("stdin")
    m = Message(file.read(), bitshares_instance=ctx.bitshares)
    try:
        if m.verify():
            print_message("Verified", "success")
        else:
            print_message("not verified", "error")
    except InvalidMessageSignature:
        print_message("Signature INVALID!", "error")