class_docstr: All gather tokens among the tensor parallel ranks
class_docstr_tok: ["All","gather","tokens","among","the","tensor","parallel","ranks"]
code: def backward(ctx, grad_output):
      return _drop_tokens(grad_output, ctx.dim), None
  
file_path: H2O/h2o_flexgen/benchmark/third_party/DeepSpeed/deepspeed/moe/mappings.py
imports: import torch
  import deepspeed
label_desc: Use image node_id 3 for calling the _GatherTokens obj's underlying member method code with example usage: obj.backward(ctx, grad_output) and returns: _drop_tokens,  None