code: def set_aggr(self, aggr):
      self.conv1.aggr = aggr
      self.conv2.aggr = aggr
      self.conv3.aggr = aggr
  
file_path: pytorch_geometric/examples/graph_saint.py
imports: import argparse
  import os.path
  import torch
  import torch.nn.functional
  from torch_geometric.datasets import Flickr
  from torch_geometric.loader import GraphSAINTRandomWalkSampler
  from torch_geometric.nn import GraphConv
  from torch_geometric.typing import WITH_TORCH_SPARSE
  from torch_geometric.utils import degree
label_desc: Use image node_id 2 for calling the Net obj's underlying member method code with example usage: obj.set_aggr(aggr) without return types