private void addSyntheticEdge(Collection<GraphEdge> result,GraphEdge original,GraphNode head,GraphNode tail){
  result.add(new GraphEdge(head,tail,original.getRelation()));
}

private void addSyntheticEdge ( Collection < GraphEdge > result , GraphEdge original , GraphNode head , GraphNode tail ) { result . add ( new GraphEdge ( head , tail , original . getRelation ( ) ) ) ; }
synthesize a new edge , and add it to the result . the new edge goes from head to tail , and it ' s relationship type is obtained from the original edge .
