code: def positions_for(tokens, past_length):
      batch_size = tokens.shape[0]
      nsteps = tokens.shape[1]
      return expand_tile(past_length + np.arange(nsteps), batch_size)
  
imports: import json
  import os
  import sys
  import jax.numpy
  import numpy
  import objax
  from objax.variable import TrainVar
label_desc: Use image node_id 8 for calling a global function with example usage: positions_for(tokens, past_length) and returns: expand_tile