code: def define_graph(self):
      inputs, boxes, labels = self.input(name="Reader")
      return inputs, boxes.gpu(), labels
  
imports: import nvidia.dali.ops
  import os
  from nvidia.dali.pipeline import Pipeline
  from test_utils import get_dali_extra_path
  from nose_utils import assert_raises
label_desc: Use image node_id 2 for calling the DetectionPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: inputs,  boxes,  labels