docstr: Constructs messages in analogy to :math:`\phi_{\mathbf{\Theta}}`
  for each edge in :math:`(i,j) \in \mathcal{E}`.
  Can take any argument which was initially passed to :meth:`propagate`.
  In addition, features can be lifted to the source node :math:`i` and
  target node :math:`j` by appending :obj:`_i` or :obj:`_j` to the
  variable name, *.e.g.* :obj:`x_i` and :obj:`x_j`.
docstr_tok: ["Constructs","messages","in","analogy","to",":","math",":","`","\\phi_","{","\\mathbf","{","\\Theta","}","}","`","for","each","edge","in",":","math",":","`","(","i",",","j",")","\\in","\\mathcal","{","E","}","`",".","Can","take","any","argument","which","was","initially","passed","to",":","meth",":","`","propagate","`",".","In","addition",",","features","can","be","lifted","to","the","source","node",":","math",":","`","i","`","and","target","node",":","math",":","`","j","`","by","appending",":","obj",":","`","_i","`","or",":","obj",":","`","_j","`","to","the","variable","name",",","*",".e.g",".","*",":","obj",":","`","x_i","`","and",":","obj",":","`","x_j","`","."]
code: def message(self, x_j):  # pragma: no cover
      r"""Constructs messages in analogy to :math:`\phi_{\mathbf{\Theta}}`
      for each edge in :math:`(i,j) \in \mathcal{E}`.
      Can take any argument which was initially passed to :meth:`propagate`.
      In addition, features can be lifted to the source node :math:`i` and
      target node :math:`j` by appending :obj:`_i` or :obj:`_j` to the
      variable name, *.e.g.* :obj:`x_i` and :obj:`x_j`."""
  
      return x_j
  
imports: from torch_geometric.nn import GATConv, GCNConv, ChebConv, SAGEConv, GatedGraphConv, ARMAConv, SGConv
  import torch_geometric.nn
  import torch
  from torch import nn
  import torch.nn.functional
  import inspect
  import sys
  from torch_scatter import scatter_add
  import torch_scatter
  from torch.nn import Parameter
  from torch_geometric.nn.inits import glorot, zeros
  from torch_geometric.utils import remove_self_loops, add_self_loops, add_remaining_self_loops, softmax
label_desc: Use image node_id 3 for calling the MessagePassing obj's underlying member method code with example usage: obj.message(x_j) and returns: x_j