code: def __init__(self):
      super().__init__()
      self.aggr = SumAggregation()
  
imports: import torch
  from torch_geometric.nn import SumAggregation
  from torch_geometric.nn.to_fixed_size_transformer import to_fixed_size
label_desc: Use image node_id 1 to create a new Model object from inherited base classes: torch.nn with example: obj = Model()