code: def step_num():
      return tf.to_float(tf.train.get_or_create_global_step())
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tensor2tensor.layers import common_layers
  from tensor2tensor.utils import quantization
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling a global function with example usage: step_num() and returns: tf