code: def define_graph(self):
      inputs, labels = self.input(name="Reader")
  
      images = self.decode(inputs)
      if self.device == "gpu":
          images = images.gpu()
      if self.prime_size:
          images = fn.resize(images, resize_x=101, resize_y=43)
      mask = fn.random.coin_flip(seed=42) if self.do_mask else None
      images = fn.cast(images, dtype=self.dtype)
      images = self.water(images, mask=mask)
      return images
  
imports: import nose_utils
  from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.ops
  import nvidia.dali.fn
  import nvidia.dali.types
  import nvidia.dali
  import numpy
  import os
  import cv2
  from test_utils import compare_pipelines
  from test_utils import get_dali_extra_path
label_desc: Use image node_id 2 for calling the WaterPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: images