public function isVertexSink(Vertex $vertex)
    {
        foreach ($vertex->getEdges() as $edge) {
            if ($edge->hasVertexStart($vertex)) {
                return false;
            }
        }

        // reach this point: no edge away from this vertex
        return true;
    }
public function isVertexSink(Vertex $vertex)
    {
        foreach ($vertex->getEdges() as $edge) {
            if ($edge->hasVertexStart($vertex)) {
                return false;
            }
        }

        // reach this point: no edge away from this vertex
        return true;
    }
public function isVertexSink ( Vertex $ vertex ) { foreach ( $ vertex -> getEdges ( ) as $ edge ) { if ( $ edge -> hasVertexStart ( $ vertex ) ) { return false ; } } // reach this point: no edge away from this vertex return true ; }
checks whether this vertex is a sink, i.e. its outdegree is zero

@param Vertex $vertex
@return boolean
@uses Edge::hasVertexStart()
@see self::getDegreeOutVertex()
checks whether this vertex is a sink i . e . its outdegree is zero