code: def __init__(self, input_size, hidden_size, aggr_type="sum"):
      super(GraphSageConv, self).__init__()
      assert aggr_type in [
          "sum",
          "mean",
          "max",
          "min",
      ], "Only support 'sum', 'mean', 'max', 'min' built-in receive type."
  
      self.aggr_type = aggr_type
      self.self_linear = nn.Linear(input_size, hidden_size)
      self.neigh_linear = nn.Linear(input_size, hidden_size)
  
imports: import paddle
  import paddle.nn
  from .base_conv import BaseConv
label_desc: Use image node_id 1 to create a new SageConv object from inherited base classes: BaseConv with example: obj = SageConv(input_size, hidden_size, aggr_type)