docs: def get_num_filters(layer):
      """Determines the number of filters within the given `layer`.
  
      Args:
          layer: The keras layer to use.
  
      Returns:
          Total number of filters within `layer`.
          For `keras.layers.Dense` layer, this is the total number of outputs.
      """
      # Handle layers with no channels.
      if K.ndim(layer.output) == 2:
          return K.int_shape(layer.output)[-1]
  
      channel_idx = 1 if K.image_data_format() == 'channels_first' else -1
      return K.int_shape(layer.output)[channel_idx]