workaround flake8 E125/ yapf issue

                           [x.node_features for x in featurized])

    valid_attempts = 0

    for _ in range(10):

      # try to catch tensorflow internal errors

      try:

      # force clear tensor flow backend

      keras_clear_session()

      # create new model

      gan = MolGAN(learning_rate=ExponentialDecay(0.001, 0.9, 5000))

      # to avoid flake8 E125/yapf incompatibility

      s = gan.batch_size

      # generate input

      def iterbatches(epochs):

        for __ in range(epochs):

            for batch in dataset.iterbatches(

                    batch_size=gan.batch_size, pad_batches=True):

          for batch in dataset.iterbatches(batch_size=s, pad_batches=True):

            adjacency_tensor = one_hot(batch[0], gan.edges)

            node_tesor = one_hot(batch[1], gan.nodes)

            }

      # train model

        gan.fit_gan(

            iterbatches(1000), generator_steps=0.2, checkpoint_interval=0)

      gan.fit_gan(iterbatches(1000), generator_steps=0.2, checkpoint_interval=0)

      # generate sample

      g = gan.predict_gan_generator(1000)

          list(filter(lambda x: x is not None, generated_molecules)))

      if valid_molecules_count:

        valid_attempts = valid_attempts + 1

      except InternalError:

        print(

            'Tensor flow internal error raised. Make sure no other instance of tensorflow e.g. jupyter notebook, is running.'

        )

        break

    assert valid_attempts > 0