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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 stop(name, call=None):
 """ Stop a running machine. @param name: Machine to stop @type name: str @param call: Must be "action" @type call: str """

    if call != 'action':
        raise SaltCloudSystemExit(
            'The instance action must be called with -a or --action.'
        )

    log.info("Stopping machine: %s", name)
    vb_stop_vm(name)
    machine = vb_get_machine(name)
    del machine["name"]
    return treat_machine_dict(machine)