code: def transformer_test(self, transformer):
      image_frame = ImageFrame.read(self.image_path)
      transformed = transformer(image_frame)
      transformed.get_image()
  
      image_frame = ImageFrame.read(self.image_path, self.sc)
      transformed = transformer(image_frame)
      images = transformed.get_image()
      images.count()
  
imports: import pytest
  import os
  from bigdl.dllib.utils.common import *
  from bigdl.dllib.feature.transform.vision.image import *
  import tempfile
label_desc: Use image node_id 4 for calling the TestLayer obj's underlying member method code with example usage: obj.transformer_test(transformer) without return types