class_docstr: :class:`DPoolPairDataGenerator` constructor.
  
  :param fixed_length_left: max length of left text.
  :param fixed_length_right: max length of right text.
  :param compress_ratio_left: the length change ratio,
      especially after normal pooling layers.
  :param compress_ratio_right: the length change ratio,
      especially after normal pooling layers.
docstr: Insert `dpool_index` into `x`.
  
  :param x: unpacked x.
  :param y: unpacked y.
docstr_tok: ["Insert","`","dpool_index","`","into","`","x","`",".",":","param","x",":","unpacked","x.",":","param","y",":","unpacked","y","."]
code: def on_batch_unpacked(self, x, y):
      """
      Insert `dpool_index` into `x`.
  
      :param x: unpacked x.
      :param y: unpacked y.
      """
      x["dpool_index"] = _dynamic_pooling_index(
          x["length_left"],
          x["length_right"],
          self._fixed_length_left,
          self._fixed_length_right,
          self._compress_ratio_left,
          self._compress_ratio_right,
      )
  
imports: import numpy
  from matchzoo.data_generator.callbacks import Callback
label_desc: Use image node_id 2 for calling the DynamicPooling obj's underlying member method code with example usage: obj.on_batch_unpacked(x, y) without return types