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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 shutdown(self, vm_names=None, reboot=False):
 """ Shutdown this prefix Args: vm_names(list of str):
 List of the vms to shutdown reboot(bool):
 If true, reboot the requested vms Returns: None """

        self.virt_env.shutdown(vm_names, reboot)