code: def define_graph(self):
      self.data = self.inputs()
      out = self.lookup(self.data)
      out = self.cast(out)
      return out
  
imports: import numpy
  import random
  from nvidia.dali import fn, types, ops, pipeline_def
  from nvidia.dali.pipeline import Pipeline
  from test_utils import RandomlyShapedDataIterator
  from test_utils import compare_pipelines
  from nose2.tools import params
label_desc: Use image node_id 2 for calling the LookupTablePythonOpPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: out