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ml-agents/mlagents/trainers/trainer/rl_trainer.py

                     except AgentManagerQueue.Empty:
                         break
                 if self.threaded and not _queried:
-                    # Avoid busy-waiting
+                    # Yield thread to avoid busy-waiting
                     time.sleep(0.0001)
         if self.should_still_train:
             if self._is_ready_update():