public function testComponents()
 {
     // 1 -- 2, 3 -> 4, 5
     $graph = new Graph();
     $v1 = $graph->createVertex(1);
     $v2 = $graph->createVertex(2);
     $v3 = $graph->createVertex(3);
     $v4 = $graph->createVertex(4);
     $v5 = $graph->createVertex(5);
     $e1 = $v1->createEdge($v2);
     $e2 = $v3->createEdgeTo($v4);
     $alg = new AlgorithmConnected($graph);
     $this->assertEquals(3, $alg->getNumberOfComponents());
     $this->assertFalse($alg->isSingle());
     $graphs = $alg->createGraphsComponents();
     $this->assertCount(3, $graphs);
     $ge = new Graph();
     $ge->createVertex(1)->createEdge($ge->createVertex(2));
     $this->assertGraphEquals($ge, $alg->createGraphComponentVertex($v2));
     $ge = new Graph();
     $ge->createVertex(5);
     $this->assertEquals($ge, $alg->createGraphComponentVertex($v5));
 }
 private function disconnectGraph()
 {
     $components = new ConnectedComponents($this->graph);
     $this->disconnections = $components->createGraphsComponents();
 }