code: def running_mean_init(shape, fill_value=0):
      return (np.full(shape, fill_value), np.array(0))
  
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 1 for calling a global function with example usage: running_mean_init(shape, fill_value) and returns: np,  np