Calling a __call__ method on tf.keras.layers.Layer

I am looking at some code from Google (google-research/attention_networks.py at c56b47713b08c95ad427d5f93ee0dbb9ad008964 · google-research/google-research · GitHub). I am new to TensorFlow and I don’t really understand what line 491 is doing. It’s passing some normalized kwargs to the call method of tf.keras.layers.Layer, which gives back those three ouputs. Is this just a sequence of dense layers?

Thanks