#NEWLINE# @ check_instance_cell #NEWLINE# def _attach_volume( self , context , instance , volume_id , device , disk_bus , device_type ) : #NEWLINE# #INDENT# 'Attach an existing volume to an existing instance.' #NEWLINE# volume = self . volume_api . get ( context , volume_id ) #NEWLINE# self . volume_api . check_attach ( context , volume , instance = instance ) #NEWLINE# return self . _call_to_cells ( context , instance , 'attach_volume' , volume_id , device , disk_bus , device_type )