Sample code for custom evaluation

Hi, The custom eval exmaple failed [ray/custom_eval.py at master · ray-project/ray · GitHub] when “evaluation_num_workers” = 1

File “ppo_Training.py”, line 78, in custom_eval_function
worker_1.foreach_env.remote(lambda env: env.set_intermediate_flags(True, True, validationSeed, validationTrial))
AttributeError: ‘list’ object has no attribute ‘foreach_env’

could anyone please provide a sample code, such that it works with one eval worker.