code: def get_expand_pad_mask(inputs, pad_idx):
      """
      get padding mask from the input token idx
      inputs: [batch_size, time_steps]
      mask: [batch_size, time_steps, 1]
      """
      pad_mask = tf.cast(tf.math.greater(inputs, pad_idx), tf.float32)
      pad_mask = tf.expand_dims(pad_mask, -1)
      return pad_mask
  
file_path: delta/delta/layers/utils.py
imports: import math
  import delta.compat
  from tensorflow.python.keras import backend
  import delta.utils
label_desc: Use image node_id 7 for calling a global function with example usage: get_expand_pad_mask(inputs, pad_idx) and returns: pad_mask