class_docstr: Helper class which loads and stores dataset metadata.
docstr: Returns target class for image with given ID.
docstr_tok: ["Returns","target","class","for","image","with","given","ID","."]
code: def get_target_class(self, image_id):
      """Returns target class for image with given ID."""
      return self._target_classes[image_id]
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import argparse
  import csv
  import json
  import os
  import subprocess
  import numpy
  from PIL import Image
label_desc: Use image node_id 3 for calling the DatasetMetadata obj's underlying member method code with example usage: obj.get_target_class(image_id) and returns: self