code: def value(self):
      return self._foo
  
imports: import itertools
  from absl.testing import parameterized
  import numpy
  from sonnet.src import batch_norm
  from sonnet.src import initializers
  from sonnet.src import test_utils
  import tensorflow
label_desc: Use image node_id 3 for calling the TestMetric obj's underlying member method code with example usage: obj.value() and returns: self