code: def ensure_comm(t, comm):
      if comm is None:
          comm = get_torch_default_comm()
      global _moe_group
      _moe_group = comm
      fmoe_cuda.ensure_nccl(comm, t)
  
imports: import torch
  from torch.autograd import Function
  import fmoe_cuda
  from .utils import get_torch_default_comm
label_desc: Use image node_id 1 for calling a global function with example usage: ensure_comm(t, comm) without return types