code: def testContains(self):
      hparams = hparam.HParams(foo=1)
      self.assertTrue("foo" in hparams)
      self.assertFalse("bar" in hparams)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tensor2tensor.utils import hparam
  import tensorflow.compat.v1
label_desc: Use image node_id 2 for calling the HParamsTest obj's underlying member method code with example usage: obj.testContains() without return types