message: [tensorflow] Add super(x, self).setUp() to `losses_test.py`.
  Without this, graphs aren't cleared between tests.
diff: @@ -40,6 +40,7 @@ from tensorflow.python.training import momentum as momentum_lib
  class AbsoluteDifferenceLossTest(test.TestCase):
  def setUp(self):
  + super(AbsoluteDifferenceLossTest, self).setUp()
  self._predictions = constant_op.constant([4, 8, 12, 8, 1, 3], shape=(2, 3))
  self._labels = constant_op.constant([1, 9, 2, -5, -2, 6], shape=(2, 3))
  @@ -608,6 +609,7 @@ class SigmoidCrossEntropyLossTest(test.TestCase):
  class LogLossTest(test.TestCase):
  def setUp(self):
  + super(LogLossTest, self).setUp()
  predictions = np.asarray([.9, .2, .2, .8, .4, .6]).reshape((2, 3))
  labels = np.asarray([1.0, 0.0, 1.0, 1.0, 0.0, 0.0]).reshape((2, 3))
  @@ -868,6 +870,7 @@ class HuberLossTest(test.TestCase):
  class MeanSquaredErrorTest(test.TestCase):
  def setUp(self):
  + super(MeanSquaredErrorTest, self).setUp()
  self._predictions = constant_op.constant([4, 8, 12, 8, 1, 3], shape=(2, 3))
  self._labels = constant_op.constant([1, 9, 2, -5, -2, 6], shape=(2, 3))
  @@ -941,6 +944,7 @@ class MeanSquaredErrorTest(test.TestCase):
  class MeanPairwiseSquaredErrorTest(test.TestCase):
  def setUp(self):
  + super(MeanPairwiseSquaredErrorTest, self).setUp()
  self._predictions = np.array([[4, 8, 12], [8, 1, 3]])
  self._labels = np.array([[1, 9, 2], [-5, -5, 7]])
  @@ -1167,6 +1171,7 @@ class MeanPairwiseSquaredErrorTest(test.TestCase):
  class CosineDistanceLossTest(test.TestCase):
  def setUp(self):
  + super(CosineDistanceLossTest, self).setUp()
  self._predictions = np.asarray([
  [1, 0, 0], # Batch 1
  [0, 0, -1],
  @@ -1290,6 +1295,7 @@ class AddLossTest(test.TestCase):
  class ComputeWeightedLossTest(test.TestCase):
  def setUp(self):
  + super(ComputeWeightedLossTest, self).setUp()
  self._shape = (3, 2, 4)
  raw_losses = np.zeros(self._shape)
  next_loss = 0.0
  