code: def read(self):
      self._q.join()
      result = self._current_data
      self.file_name = None
      self._current_data = None
      return result
  
imports: import atexit
  import csv
  import os
  import threading
  from collections import OrderedDict, deque
  from time import sleep
  import numpy
  from nnabla.config import nnabla_config
  from nnabla.logger import logger
  from nnabla.utils.communicator_util import current_communicator
  from six.moves import queue
  from .data_source import DataSource
  from .data_source_loader import FileReader, load
label_desc: Use image node_id 6 for calling the CachePrefetcher obj's underlying member method code with example usage: obj.read() and returns: result