code: def denoise_v1_z15():
      """Replace tokens instead of masking."""
      hparams = denoise_v1_m15()
      hparams.noising_spec_train = {
          "type": "random_zipfian",
          "prob": 0.15,
      }
      return hparams
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tensor2tensor.models import mtf_transformer
  from tensor2tensor.models import mtf_transformer2
  from tensor2tensor.models.research import moe
  from tensor2tensor.utils import registry
label_desc: Use image node_id 38 for calling a global function with example usage: denoise_v1_z15() and returns: hparams