public function testReplaceResourceTriples()
{
$graph = new ExtendedGraph();
$graph->add_literal_triple('http://some/subject/1', 'http://some/predicate', 'some object');
$graph->add_resource_triple('http://some/subject/2', 'http://some/predicate', 'http://some/subject/1');
$graph->replace_resource_triples('http://some/subject/2', 'http://some/predicate', 'http://some/subject/3');
$index = $graph->get_index();
$this->assertEquals('http://some/subject/3', $index['http://some/subject/2']['http://some/predicate'][0]['value'], "http://some/subject/3");
}