public function getVerticesEdgeFrom()
    {
        $ret = array();
        foreach ($this->getEdgesIn() as $edge) {
            $ret []= $edge->getVertexFromTo($this);
        }

        return new Vertices($ret);
    }
public function getVerticesEdgeFrom()
    {
        $ret = array();
        foreach ($this->getEdgesIn() as $edge) {
            $ret []= $edge->getVertexFromTo($this);
        }

        return new Vertices($ret);
    }
public function getVerticesEdgeFrom ( ) { $ ret = array ( ) ; foreach ( $ this -> getEdgesIn ( ) as $ edge ) { $ ret [ ] = $ edge -> getVertexFromTo ( $ this ) ; } return new Vertices ( $ ret ) ; }
get set of all Vertices that have an edge TO this vertex

If there are multiple parallel edges from the same Vertex, it will be
returned several times in the resulting Set of Vertices. If you only
want unique Vertex instances, use `getVerticesDistinct()`.

@return Vertices
@uses Vertex::getEdgesIn()
@uses Edge::getVerticesFromTo()
get set of all Vertices that have an edge TO this vertex