code: def test_variables_receive_gradients(self):
      x = tf.random.uniform((1, 2), dtype=tf.float32)
      layer = gdn.GDN(inverse=False, rectify=True)
      with tf.GradientTape() as g:
          y = layer(x)
      grads = g.gradient(y, layer.trainable_weights)
      self.assertLen(grads, 2)
      self.assertNotIn(None, grads)
      grad_shapes = [tuple(g.shape) for g in grads]
      weight_shapes = [tuple(w.shape) for w in layer.trainable_weights]
      self.assertSameElements(grad_shapes, weight_shapes)
  
imports: import os
  from absl.testing import parameterized
  import tensorflow
  from tensorflow_compression.python.layers import gdn
  from tensorflow_compression.python.layers import parameters
label_desc: Use image node_id 14 for calling the GDNTest obj's underlying member method code with example usage: obj.test_variables_receive_gradients() without return types