code: def forward(self, x):
      return th.sigmoid(self.linear(self.norm(x)))
  
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 HaltingUnit obj's underlying member method code with example usage: obj.forward(x) and returns: th