Gliph\Graph\DirectedAdjacencyList::outDegreeOf PHP Method

    public function outDegreeOf($vertex)
    {
        if (!$this->hasVertex($vertex)) {
            throw new NonexistentVertexException('Vertex is not in the graph, out-degree information cannot be provided', E_WARNING);
        }
        return $this->vertices[$vertex]->count();
    }