code: def mean_q(y_true, y_pred):
      return K.mean(K.max(y_pred, axis=-1))
  
imports: from __future__ import division
  import warnings
  import keras.backend
  from keras.models import Model
  from keras.layers import Lambda, Input, Layer, Dense
  from rl.core import Agent
  from rl.policy import EpsGreedyQPolicy, GreedyQPolicy
  from rl.util import *
label_desc: Use image node_id 1 for calling a global function with example usage: mean_q(y_true, y_pred) and returns: K