code: def pre_func(self, fields="qkv", l=0):
      layer = self.layer
  
      def func(nodes):
          x = nodes.data["x"]
          if fields == "kv":
              norm_x = x
          else:
              norm_x = layer.sublayer[l].norm(x)
          return layer.self_attn.get(norm_x, fields)
  
      return func
  
imports: from .attention import *
  from .layers import *
  from .functions import *
  from .embedding import *
  import dgl.function
  import torch
  import torch.nn.init
label_desc: Use image node_id 2 for calling the UDecoder obj's underlying member method code with example usage: obj.pre_func(fields, l) and returns: func, layer