class_docstr: Dataset of zipped image and label pairs.
  
  This dataset is zip version of :class:`LabeledImageDataset`. It
  takes a zipfile like :class:`ZippedImageDataset`. The label file
  shall contain lines like text file used in
  :class:`LabeledImageDataset`, but a filename in each line of the
  label file shall match with a file in the zip archive.
  
  Args:
      zipfilename (str): Path to a zipfile with images
      labelfilename (str): Path to a label file. ``i``-th line shall
          contain a filename and an integer label that corresponds
          to the ``i``-th sample. A filename in the label file shall
          match with a filename in the zip file given with
          `zipfilename`.
      dtype: Data type of resulting image arrays. ``chainer.config.dtype`` is
          used by default (see :ref:`configuration`).
      label_dtype: Data type of the labels.
code: def get_example(self, i):
      path, int_label = self._pairs[i]
      label = numpy.array(int_label, dtype=self._label_dtype)
      return self._zipfile.get_example(path), label
  
imports: import bisect
  import io
  import os
  import threading
  import zipfile
  import numpy
  import six
  import chainer
  from chainer.dataset import dataset_mixin
label_desc: Use image node_id 3 for calling the LabeledZippedImageDataset obj's underlying member method code with example usage: obj.get_example(i) and returns: self,  label