code: def _get_activation_fn(activation):
      """Return an activation function given a string"""
      if activation == "relu":
          return F.relu
      if activation == "gelu":
          return F.gelu
      if activation == "glu":
          return F.glu
      raise RuntimeError(
          f"activation should be relu/gelu, not {activation}."
      )
  
imports: import copy
  from typing import Optional
  import torch
  import torch.nn.functional
  from torch import nn, Tensor
label_desc: Use image node_id 2 for calling a global function with example usage: _get_activation_fn(activation) and returns: F, F, F