code: def running_mean_get_mean(state):
      (mean, _) = state
      return mean
  
file_path: trax/trax/rl/normalization.py
imports: import gin
  import numpy
  from trax import fastmath
  from trax import layers
label_desc: Use image node_id 3 for calling a global function with example usage: running_mean_get_mean(state) and returns: mean