code: def _list_forward(
      layer: Model[Padded, Padded], Xs: List2d, is_train: bool
  ) -> Tuple[List2d, Callable]:
      # Assign these to locals, to keep code a bit shorter.
      list2padded = layer.ops.list2padded
      padded2list = layer.ops.padded2list
  
      Yp, get_dXp = layer(list2padded(Xs), is_train)
  
      def backprop(dYs):
          return padded2list(get_dXp(list2padded(dYs)))
  
      return padded2list(Yp), backprop
  
file_path: thinc/thinc/layers/with_padded.py
imports: from typing import Callable, List, Optional, Tuple, TypeVar, Union, cast
  from ..config import registry
  from ..model import Model
  from ..types import Array2d, Floats3d, Ints1d, List2d, Padded, Ragged
  from ..util import is_xp_array
label_desc: Use image node_id 9 for calling a global function with example usage: _list_forward(layer, Xs, is_train) and returns: padded2list,  backprop, padded2list