code: def testImg2imgTransformer(self):
      self._test_img2img_transformer(
          image_transformer_2d.Img2imgTransformer
      )
  
file_path: tensor2tensor/tensor2tensor/models/image_transformer_2d_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  from tensor2tensor.data_generators import celeba
  from tensor2tensor.data_generators import problem_hparams
  from tensor2tensor.models import image_transformer_2d
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
label_desc: Use image node_id 2 for calling the Img2imgTransformerTest obj's underlying member method code with example usage: obj.testImg2imgTransformer() without return types