class_docstr: Gated Linear Unit
code: def forward(self, x):
      if self.dropout is not None:
          x = self.dropout(x)
      x = self.fc(x)
      x = F.glu(x, dim=-1)
      return x
  
imports: from typing import Dict, List, Optional, Tuple, Union
  import torch
  import torch.nn
  import torch.nn.functional
  from darts.logging import get_logger
  from darts.utils.torch import MonteCarloDropout
label_desc: Use image node_id 3 for calling the _GatedLinearUnit obj's underlying member method code with example usage: obj.forward(x) and returns: x