def power_on(self, context, instance, network_info, block_device_info=None):
    'Power on the specified instance.'
    self._hard_reboot(context, instance, network_info, block_device_info)
Power on the specified instance.
def power_on(self, context, instance, network_info, block_device_info=None):
    
    self._hard_reboot(context, instance, network_info, block_device_info)