code: def apply(
      cls, ctx: Context, inp: Inputs, grad: torch.Tensor
  ) -> Gradients:
      raise NotImplementedError()
  
imports: import math
  from dataclasses import dataclass
  from functools import partial
  from typing import Any, Callable, List, Mapping, Optional, Set, Tuple, Type, Union
  import torch
  from ..._cpp_lib import _built_with_cuda
  from ..common import BaseOperator
  from .attn_bias import AttentionBias, BlockDiagonalMask, LowerTriangularMask, LowerTriangularMaskWithTensorBias
label_desc: Use image node_id 2 for calling the AttentionBwOpBase obj's underlying member method code with example usage: obj.apply(cls, ctx, inp, grad) without return types