code: def predict(self, obs, model_id):
      feed = {"obs": obs}
      feed = [feed]
      act = self.pred_pe[model_id].run(
          feed=feed, fetch_list=self.predict_outputs[model_id]
      )[0]
      return act
  
file_path: PARL/examples/NeurIPS2018-AI-for-Prosthetics-Challenge/opensim_agent.py
imports: import numpy
  import re
  import parl
  from parl import layers
  from paddle import fluid
  from paddle.fluid.executor import _fetch_var
  from parl.utils import logger
label_desc: Use image node_id 3 for calling the OpenSimAgent obj's underlying member method code with example usage: obj.predict(obs, model_id) and returns: act