question: public boolean unsetOrdering ( Object first , Object second ) { DigraphNode firstPONode = ( DigraphNode ) poNodes . get ( first ) ; DigraphNode secondPONode = ( DigraphNode ) poNodes . get ( second ) ; return firstPONode . removeEdge ( secondPONode ) || secondPONode . removeEdge ( firstPONode ) ; }
target:  Removes any ordering between two nodes.