code: def added(self, link):
      assert link is None or isinstance(link, chainer.Link)
      self.added_args.append((_process_time(), link))
  
imports: import time
  import unittest
  import numpy
  import chainer
  from chainer import testing
label_desc: Use image node_id 2 for calling the MyLinkHook obj's underlying member method code with example usage: obj.added(link) without return types