code: def running_mean_and_variance_update(x, state):
      (mean_state, var_state) = state
      old_mean = running_mean_get_mean(mean_state)
      mean_state = running_mean_update(x, mean_state)
      new_mean = running_mean_get_mean(mean_state)
  
      var_state = running_mean_update(
          (x - new_mean) * (x - old_mean), var_state
      )
  
      return (mean_state, var_state)
  
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 6 for calling a global function with example usage: running_mean_and_variance_update(x, state) and returns: mean_state,  var_state