code: def describe(self) -> str:
      return (
          "Accepts ``PIL.Image``, batched ``(B, C, H, W)`` and single ``(C, H, W)`` image ``torch.Tensor`` objects. "
          "The images are rescaled to ``[-1.0, 1.0]``."
      )
  
imports: from typing import Optional, Tuple
  import torch
  from torch import nn, Tensor
  from .None import functional, InterpolationMode
label_desc: Use image node_id 3 for calling the OpticalFlow obj's underlying member method code with example usage: obj.describe() and returns: str