public function testSubGraph() { $graph = new Digraph('G'); $subgraph = $graph->subgraph('foo'); $subgraph->edge(array('A', 'B')); $this->assertCount(1, $graph->getInstructions(), "Count of instructions"); $this->assertTrue($subgraph instanceof Subgraph, "Subgraph return"); $this->assertSame('foo', $subgraph->getId(), "Subgraph identifier"); $this->assertSame($graph, $subgraph->end(), "Subgraph end"); $this->assertEquals("subgraph foo {\n A -> B;\n};\n", $subgraph->render(), "Subgraph rendering"); }