class_docstr: Compute the input feature from neighbors
code: def forward(self, edges):
      pos = edges.src["pos"] - edges.dst["pos"]
      if "feat" in edges.src:
          res = torch.cat([pos, edges.src["feat"]], 1)
      else:
          res = pos
      return {"agg_feat": res}
  
imports: import dgl
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.autograd import Function
  from torch.nn import Parameter
  from torch.nn.modules.utils import _single
label_desc: Use image node_id 2 for calling the RelativePositionMessage obj's underlying member method code with example usage: obj.forward(edges) and returns: dict