class_docstr: Produce images read from a list of zip files. 
code: def open(self):
      self.archivefiles = []
      archive = zipfile.ZipFile(self._file)
      imagesInArchive = archive.namelist()
      for img_name in imagesInArchive:
          if img_name.endswith(".jpg"):
              self.archivefiles.append((archive, img_name))
  
imports: import argparse
  import numpy
  import os
  import zipfile
  import cv2
  from tensorpack import LMDBSerializer, MapDataComponent, RNGDataFlow
label_desc: Use image node_id 2 for calling the ImageDataFromZIPFile obj's underlying member method code with example usage: obj.open() without return types