code: def new_reader(self, **kwargs):
      return self._src_ds
  
imports: from caffe2.python.dataio import CompositeReader, CompositeReaderBuilder, ReaderBuilder, ReaderWithDelay, ReaderWithLimit, ReaderWithTimeLimit
  from caffe2.python.dataset import Dataset
  from caffe2.python.db_file_reader import DBFileReader
  from caffe2.python.pipeline import pipe
  from caffe2.python.schema import Struct, NewRecord, FeedRecord
  from caffe2.python.session import LocalSession
  from caffe2.python.task import TaskGroup, final_output, WorkspaceType
  from caffe2.python.test_util import TestCase
  from caffe2.python.cached_reader import CachedReader
  from caffe2.python import core, workspace, schema
  from caffe2.python.net_builder import ops
  import numpy
  import numpy.testing
  import os
  import shutil
  import unittest
  import tempfile
label_desc: Use image node_id 4 for calling the TestReaderBuilder obj's underlying member method code with example usage: obj.new_reader() and returns: self