code: def message(self, weight_j: Tensor, edge_weight: OptTensor) -> Tensor:
      if edge_weight is None:
          return weight_j
      else:
          return edge_weight.view(-1, 1) * weight_j
  
imports: import math
  import torch
  from torch import Tensor
  from torch.nn import BatchNorm1d, Parameter
  from torch_geometric.nn import inits
  from torch_geometric.nn.conv import MessagePassing
  from torch_geometric.nn.models import MLP
  from torch_geometric.typing import Adj, OptTensor
  from torch_geometric.utils import spmm
label_desc: Use image node_id 4 for calling the SparseLinear obj's underlying member method code with example usage: obj.message(weight_j, edge_weight) and returns: weight_j, unknown