docstr: Function needed to be used as an iterator.
code: def __next__(self):
      """Function needed to be used as an iterator."""
      return next(self.batch_iterator)
  
imports: import abc
  import glob
  import logging
  import os
  import shelve
  import shutil
  import tempfile
  from datetime import datetime
  import numpy
  import tensorflow
  from .graph_partitioner import PARTITION_ALGO_REGISTRY, AbstractGraphPartitioner
label_desc: Use image node_id 12 for calling the PartitionDataManager obj's underlying member method code with example usage: obj.__next__() and returns: next