code: def update_truncate_length(hparams, length):
      hparams.max_target_seq_length = length
      hparams.min_length = length
      # If using relative attention, set max relative distance to be half
      # the max training length.
      hparams.max_relative_position = int(length / 2.0)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tensor2tensor.models import transformer
  from tensor2tensor.utils import registry
label_desc: Use image node_id 2 for calling a global function with example usage: update_truncate_length(hparams, length) without return types