code: def input_size_total(self):
      return sum(
          size if name in self.input_embedding_flags else size
          for name, size in self.input_sizes.items()
      )
  
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 2 for calling the _VariableSelectionNetwork obj's underlying member method code with example usage: obj.input_size_total() and returns: sum