code: def apool(self,
                k_height,
                k_width,
                d_height=2,
                d_width=2,
                mode="VALID",
                input_layer=None,
                num_channels_in=None):
          
          return self._pool("apool", pooling_layers.average_pooling2d, k_height,
                            k_width, d_height, d_width, mode, input_layer,
                            num_channels_in)
docs: Construct an average pooling layer.