code: def bmm(a: torch.Tensor, b: torch.Tensor) -> torch.Tensor:
      if _has_cpp_library:
          if isinstance(a, SparseCS):
              return a.spmm(b)
          if a.is_sparse:
              return _sparse_bmm(a, b)
      return a @ b
  
file_path: xformers/xformers/components/attention/core.py
imports: import logging
  import math
  from contextlib import nullcontext
  from functools import lru_cache
  from typing import Optional, Union
  import torch
  from xformers import _has_cpp_library, _is_triton_available
  from xformers.components.attention.attention_mask import AttentionMask
label_desc: Use image node_id 5 for calling a global function with example usage: bmm(a, b) and returns: unknown, a, _sparse_bmm