code: def test_r1_regularization_shape_correct_sequence_input(self):
      discriminator = tf.keras.Sequential()
      discriminator.add(tf.keras.layers.Concatenate())
      discriminator.add(tf.keras.layers.Reshape((50,)))
      discriminator.add(tf.keras.layers.Dense(units=1))
      real_data = (tf.ones(shape=(3, 5, 5)), tf.ones(shape=(3, 5, 5)))
  
      r1_regulatiztion = losses.r1_regularization(
          real_data=real_data, discriminator=discriminator
      )
      r1_regulatiztion_value = self.evaluate(r1_regulatiztion)
  
      self.assertSequenceEqual(r1_regulatiztion_value.shape, (3,))
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow_graphics.projects.gan import losses
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 12 for calling the LossesTest obj's underlying member method code with example usage: obj.test_r1_regularization_shape_correct_sequence_input() without return types