docs: def _construct_w(self, inputs):
      """Connects the module into the graph, with input Tensor `inputs`.
  
      Args:
        inputs: A 4D Tensor of shape:
            [batch_size, input_height, input_width, input_channels]
            and of type `tf.float16`, `tf.bfloat16` or `tf.float32`.
  
      Returns:
        A tuple of two 4D Tensors, each with the same dtype as `inputs`:
          1. w_dw, the depthwise weight matrix, of shape:
            [kernel_size, input_channels, channel_multiplier]
          2. w_pw, the pointwise weight matrix, of shape:
            [1, 1, channel_multiplier * input_channels, output_channels].
      """
      depthwise_weight_shape = self._kernel_shape + (self._input_channels,
                                                     self._channel_multiplier)
      pointwise_input_size = self._channel_multiplier * self._input_channels
      pointwise_weight_shape = (1, 1, pointwise_input_size, self._output_channels)
  
      if "w_dw" not in self._initializers:
        fan_in_shape = depthwise_weight_shape[:2]
        self._initializers["w_dw"] = create_weight_initializer(fan_in_shape,
                                                               dtype=inputs.dtype)
  
      if "w_pw" not in self._initializers:
        fan_in_shape = pointwise_weight_shape[:3]
        self._initializers["w_pw"] = create_weight_initializer(fan_in_shape,
                                                               dtype=inputs.dtype)
  
      w_dw = tf.get_variable(
          "w_dw",
          shape=depthwise_weight_shape,
          dtype=inputs.dtype,
          initializer=self._initializers["w_dw"],
          partitioner=self._partitioners.get("w_dw", None),
          regularizer=self._regularizers.get("w_dw", None))
  
      w_pw = tf.get_variable(
          "w_pw",
          shape=pointwise_weight_shape,
          dtype=inputs.dtype,
          initializer=self._initializers["w_pw"],
          partitioner=self._partitioners.get("w_pw", None),
          regularizer=self._regularizers.get("w_pw", None))
  
      return w_dw, w_pw