class_docstr: This plugin adds option to call ``gc.collect`` after each test
code: def options(self, parser, env=os.environ):
      env_opt = "PERFORM_GC"
      parser.add_option(
          "--perform-gc",
          action="store_true",
          dest="performGC",
          default=env.get(env_opt, False),
          help="Call gc.collect() after each test",
      )
  
file_path: catboost/contrib/python/matplotlib/py2/matplotlib/testing/_nose/plugins/performgc.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import gc
  import os
  from nose.plugins import Plugin
label_desc: Use image node_id 1 for calling the PerformGC obj's underlying member method code with example usage: obj.options(parser, env) without return types