code: private void assignNodeLinkProperty(Node node, Relation relation, Node childNode)
      {
          // Construct Node Link for this relationship
          NodeLink nodeLink = new NodeLink(node.getNodeId(), childNode.getNodeId());
          setLink(node, relation, childNode, nodeLink);
      }
docs: On assigning node link properties
  
  @param node
  node
  @param relation
  relation
  @param childNode
  child node