question: @ RpcMethod public void transferImage ( String imageId , String source , String destination , ServerAddress destinationHost , AsyncMethodCallback < Host . AsyncClient . copy_image_call > handler ) throws RpcException { ensureClient ( ) ; TransferImageRequest transferImageRequest = new TransferImageRequest ( ) ; transferImageRequest . setDestination_datastore_id ( destination ) ; transferImageRequest . setDestination_host ( destinationHost ) ; transferImageRequest . setSource_datastore_id ( source ) ; transferImageRequest . setSource_image_id ( imageId ) ; clientProxy . setTimeout ( TRANSFER_IMAGE_TIMEOUT_MS ) ; logger . info ( "transfer_image target {}, request {}" , getHostIp ( ) , transferImageRequest ) ; try { clientProxy . transfer_image ( transferImageRequest , handler ) ; } catch ( TException e ) { throw new RpcException ( e . getMessage ( ) ) ; } }
target:  This method performs an asynchronous Thrift call to copy an image from one host to another. On completion, the specified handler is invoked.