code: def coupling(*args, **kwargs):
      """Coupling transform layer."""
      prior_type = kwargs["hparams"].prior_type
      posterior_type = kwargs["hparams"].posterior_type
      if prior_type == "affine" or posterior_type == "affine":
          return affine_coupling(*args, **kwargs)
      elif prior_type == "additive" or posterior_type == "additive":
          return additive_coupling(*args, **kwargs)
  
file_path: tensor2tensor/tensor2tensor/layers/transformer_glow_layers.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  import numpy
  import scipy
  from tensor2tensor.layers import common_layers
  import tensor2tensor.layers.transformer_glow_layers_ops
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling a global function with example usage: coupling() and returns: affine_coupling, additive_coupling