code: def forward(
      model: Model[InT, InT], X: InT, is_train: bool
  ) -> Tuple[InT, Callable]:
      if isinstance(X, Ragged):
          return _expand_window_ragged(model, X)
      else:
          return _expand_window_floats(model, X)
  
imports: from typing import Callable, Tuple, TypeVar, Union, cast
  from ..config import registry
  from ..model import Model
  from ..types import Floats2d, Ragged
label_desc: Use image node_id 2 for calling a global function with example usage: forward(model, X, is_train) and returns: _expand_window_ragged, _expand_window_floats