getGraph() static public method

* graph
static public getGraph ( $a = '' )
 public function testAddGraphWithNamespaces()
 {
     $g2 = ARC2::getGraph()->setPrefix('ex', 'http://example.com/');
     $actual = $this->obj->addGraph($g2);
     $this->assertArrayHasKey('ex', $actual->ns);
 }