code: def dfs_assemble(
      self,
      mol_tree_msg,
      mol_vec,
      cur_mol,
      global_amap,
      fa_amap,
      cur_node_id,
      fa_node_id,
  ):
      nodes_dict = mol_tree_msg.nodes_dict
      fa_node = (
          nodes_dict[fa_node_id] if fa_node_id is not None else None
      )
      cur_node = nodes_dict[cur_node_id]
  
      fa_nid = fa_node["nid"] if fa_node is not None else -1
      prev_nodes = [fa_node] if fa_node is not None else []
  
      children_node_id = [
          v
          for v in mol_tree_msg.successors(cur_node_id).tolist()
          if nodes_dict[v]["nid"] != fa_nid
      ]
      children = [nodes_dict[v] for v in children_node_id]
      neighbors = [
          nei for nei in children if nei["mol"].GetNumAtoms() > 1
      ]
      neighbors = sorted(
          neighbors, key=lambda x: x["mol"].GetNumAtoms(), reverse=True
      )
      singletons = [
          nei for nei in children if nei["mol"].GetNumAtoms() == 1
      ]
      neighbors = singletons + neighbors
  
      cur_amap = [
          (fa_nid, a2, a1)
          for nid, a1, a2 in fa_amap
          if nid == cur_node["nid"]
      ]
      cands = enum_assemble_nx(
          cur_node, neighbors, prev_nodes, cur_amap
      )
      if len(cands) == 0:
          return None
      cand_smiles, cand_mols, cand_amap = list(zip(*cands))
  
      cands = [
          (candmol, mol_tree_msg, cur_node_id) for candmol in cand_mols
      ]
      (
          cand_graphs,
          atom_x,
          bond_x,
          tree_mess_src_edges,
          tree_mess_tgt_edges,
          tree_mess_tgt_nodes,
      ) = mol2dgl_dec(cands)
      cand_graphs = batch([g.to(mol_vec.device) for g in cand_graphs])
      atom_x = cuda(atom_x)
      bond_x = cuda(bond_x)
      cand_graphs.ndata["x"] = atom_x
      cand_graphs.edata["x"] = bond_x
      cand_graphs.edata["src_x"] = atom_x.new(
          bond_x.shape[0], atom_x.shape[1]
      ).zero_()
  
      cand_vecs = self.jtmpn(
          (
              cand_graphs,
              tree_mess_src_edges,
              tree_mess_tgt_edges,
              tree_mess_tgt_nodes,
          ),
          mol_tree_msg,
      )
      cand_vecs = self.G_mean(cand_vecs)
      mol_vec = mol_vec.squeeze()
      scores = cand_vecs @ mol_vec
  
      _, cand_idx = torch.sort(scores, descending=True)
  
      backup_mol = Chem.RWMol(cur_mol)
      for i in range(len(cand_idx)):
          cur_mol = Chem.RWMol(backup_mol)
          pred_amap = cand_amap[cand_idx[i].item()]
          new_global_amap = copy.deepcopy(global_amap)
  
          for nei_id, ctr_atom, nei_atom in pred_amap:
              if nei_id == fa_nid:
                  continue
              new_global_amap[nei_id][nei_atom] = new_global_amap[
                  cur_node["nid"]
              ][ctr_atom]
  
          cur_mol = attach_mols_nx(
              cur_mol, children, [], new_global_amap
          )
          new_mol = cur_mol.GetMol()
          new_mol = Chem.MolFromSmiles(Chem.MolToSmiles(new_mol))
  
          if new_mol is None:
              continue
  
          result = True
          for nei_node_id, nei_node in zip(children_node_id, children):
              if nei_node["is_leaf"]:
                  continue
              cur_mol = self.dfs_assemble(
                  mol_tree_msg,
                  mol_vec,
                  cur_mol,
                  new_global_amap,
                  pred_amap,
                  nei_node_id,
                  cur_node_id,
              )
              if cur_mol is None:
                  result = False
                  break
  
          if result:
              return cur_mol
  
      return None
  
imports: import copy
  import rdkit.Chem
  import torch
  import torch.nn
  import torch.nn.functional
  from dgl import batch, unbatch
  from .chemutils import attach_mols_nx, copy_edit_mol, decode_stereo, enum_assemble_nx, set_atommap
  from .jtmpn import DGLJTMPN, mol2dgl_single
  from .jtnn_dec import DGLJTNNDecoder
  from .jtnn_enc import DGLJTNNEncoder
  from .mpn import DGLMPN, mol2dgl_single
  from .nnutils import cuda
label_desc: Use image node_id 9 for calling the DGLJTNNVAE obj's underlying member method code with example usage: obj.dfs_assemble(mol_tree_msg, mol_vec, cur_mol, global_amap, fa_amap, cur_node_id, fa_node_id) and returns: None, None, cur_mol