code: def perform_operation(self, images):
      for i in range(self.custom_parameter_integer):
          pass
  
      for image in images:
          image = image.resize((image.size[0] * 2, image.size[1] * 2))
  
      return images
  
file_path: Augmentor/tests/test_custom_operations.py
imports: import os
  import sys
  import Augmentor
  from Augmentor.Operations import Operation
  import tempfile
  from PIL import Image
  import io
label_desc: Use image node_id 3 for calling the DoubleImageSize obj's underlying member method code with example usage: obj.perform_operation(images) and returns: images