public function testGetSequenceValues()
 {
     $graph = new SimpleGraph();
     $graph->add_resource_triple('http://some/subject/1', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#_4', 'http://value/4');
     $graph->add_resource_triple('http://some/subject/1', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#_2', 'http://value/2');
     $graph->add_resource_triple('http://some/subject/1', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#_3', 'http://value/3');
     $graph->add_resource_triple('http://some/subject/1', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#_5', 'http://value/5');
     $graph->add_resource_triple('http://some/subject/1', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#_1', 'http://value/1');
     $expectedArray = array('http://value/1', 'http://value/2', 'http://value/3', 'http://value/4', 'http://value/5');
     $this->assertEquals($expectedArray, $graph->get_sequence_values('http://some/subject/1'));
 }