code: def backward(ctx, do):
      seqlen_offsets = ctx.seqlen_offsets
      if seqlen_offsets is None:
          cos, sin, cu_seqlens, seqlen_offsets = ctx.saved_tensors
      else:
          cos, sin, cu_seqlens = ctx.saved_tensors
      # TD [2023-09-02]: For some reason Triton (2.0.0.post1) errors with
      # "[CUDA]: invalid device context", and cloning makes it work. Idk why. Triton 2.1.0 works.
      if not ctx.interleaved and not ctx.inplace:
          do = do.clone()
      dx = apply_rotary(
          do,
          cos,
          sin,
          seqlen_offsets=seqlen_offsets,
          cu_seqlens=cu_seqlens,
          max_seqlen=ctx.max_seqlen,
          interleaved=ctx.interleaved,
          inplace=ctx.inplace,
          conjugate=True,
      )
      return dx, None, None, None, None, None, None, None
  
imports: import math
  from typing import Optional, Tuple, Union
  import torch
  from einops import rearrange, repeat
  from flash_attn.ops.triton.rotary import apply_rotary
label_desc: Use image node_id 2 for calling the ApplyRotaryEmb obj's underlying member method code with example usage: obj.backward(ctx, do) and returns: dx,  None,  None,  None,  None,  None,  None,  None