public function testRemoveProperties()
{
$graph = new ExtendedGraph();
$graph->add_literal_triple('http://some/subject/1', 'http://some/predicate', 'some object');
$graph->add_literal_triple('http://some/subject/2', 'http://some/predicate/to/remove', 'some object');
$graph->add_resource_triple('http://some/subject/3', 'http://some/predicate/to/remove', 'http://some/other/object');
$graph->add_literal_triple('http://some/subject/4', 'http://some/predicate', 'some object');
$graph->remove_properties('http://some/predicate/to/remove');
$this->assertFalse($graph->subject_has_property('http://some/subject/2', 'http://some/predicate/to/remove'), 'should have removed triple about subject 2');
$this->assertFalse($graph->subject_has_property('http://some/subject/3', 'http://some/predicate/to/remove'), 'should have removed triple about subject 3');
}