code: def __str__(self):
      result = [
          "State Value Stream - V",
          "\tDense (num outputs = 512)",
          "\tDense (num outputs = 1)",
          "Action Advantage Stream - A",
          "\tDense (num outputs = 512)",
          "\tDense (num outputs = {})".format(self.num_actions),
          "\tSubtract(A, Mean(A))".format(self.num_actions),
          "Add (V, A)",
      ]
      return "\n".join(result)
  
file_path: coach/rl_coach/architectures/tensorflow_components/heads/dueling_q_head.py
imports: import tensorflow
  from rl_coach.architectures.tensorflow_components.layers import Dense
  from rl_coach.architectures.tensorflow_components.heads.q_head import QHead
  from rl_coach.base_parameters import AgentParameters
  from rl_coach.spaces import SpacesDefinition
label_desc: Use image node_id 3 for calling the DuelingQHead obj's underlying member method code with example usage: obj.__str__() and returns: str