code: def output_state_size(self, message_input_size: int) -> int:
      pass
  
file_path: ptgnn/ptgnn/neuralmodels/gnn/messagepassing/abstractmessagepassing.py
imports: import torch
  from abc import abstractmethod
  from torch import nn
  from torch_scatter import scatter
  from typing import Dict, List, Tuple
label_desc: Use image node_id 2 for calling the AbstractMessageAggregation obj's underlying member method code with example usage: obj.output_state_size(message_input_size) without return types