: Start the knowledge service to generate and transfer knowledge data. In GPU mode, the devices to execute knowledge prediction will be determined by the
environment variable **FLAGS\_selected\_gpus**, or by **CUDA\_VISIBLE\_DEVICES** if it is not set, and by **CPU\_NUM** (default 1) in CPU mode. Only supported in static graph.
: Register one teacher model and assign the order number to it as its id, with the file path (offline mode) or IP address (online mode) that the teacher model writes knowledge data to.