question: public Path ( final Vertex v0 , final Vertex v1 , final EdgeSample edgeSample ) { if ( v0 == null ) throw new IllegalArgumentException ( ) ; if ( v1 == null ) throw new IllegalArgumentException ( ) ; if ( v0 . sample == null ) throw new IllegalArgumentException ( ) ; if ( edgeSample == null ) throw new IllegalArgumentException ( ) ; if ( edgeSample . getSample ( ) == null ) throw new IllegalArgumentException ( ) ; this . vertices = new Vertex [ ] { v0 , v1 } ; this . preds = getPredicates ( vertices ) ; this . edgeSample = edgeSample ; this . sumEstRead = v0 . sample . estCard + edgeSample . estRead ; this . sumEstCard = edgeSample . estCard ; this . sumEstCost = getCost ( this . sumEstRead , this . sumEstCard ) ; }
target:  Create a path from a single edge.