Readded parser argument.

Signed-off-by: simonsays1980 <simon.zehnder@gmail.com>

rllib/examples/evaluation/evaluation_parallel_to_training.py

@@ -94,6 +94,12 @@
     evaluation_interval=1,
     evaluation_duration_unit="timesteps",
 )
+parser.add_argument(
+    "--evaluation-parallel-to-training-wo-thread",
+    action="store_true",
+    help="A debugging setting that disables using a threadpool when evaluating in "
+    "parallel to training. Use for testing purposes only!",
+)
 
 
 class AssertEvalCallback(DefaultCallbacks):