assertTrue( $accumulator->add('id1')); $this->assertTrue( $accumulator->add('id2')); $this->assertFalse($accumulator->add('id1')); // repeated id // you can also access the properties (they're public) $this->assertTrue( isset($accumulator->ids['id2']) ); } function testLoad() { $accumulator = new HTMLPurifier_IDAccumulator(); $accumulator->load(array('id1', 'id2', 'id3')); $this->assertFalse($accumulator->add('id1')); // repeated id $this->assertTrue($accumulator->add('id4')); } }