code: def get_activation(act: str) -> Callable:
      if act is None or act == "relu":
          return torch.nn.ReLU()
      elif act == "gelu":
          return torch.nn.GELU()
      elif act == "swiglu":
          return SwiGLU
      else:
          raise NotImplementedError("Unsupported activation function")
  
imports: import contextlib
  import os
  from typing import Any, Callable, Dict, List, Optional, Tuple
  import torch
  import torch.distributed
  import torch.nn
  import torch.nn.functional
  from colossalai.moe.manager import MOE_MANAGER
  from colossalai.tensor.moe_tensor.api import get_dp_group, get_dp_group_ranks, get_ep_size, is_moe_tensor
  from colossalai.utils import get_current_device
label_desc: Use image node_id 3 for calling a global function with example usage: get_activation(act) and returns: torch, torch, SwiGLU