public function test_assoc_2() { $s1 = array('color', 'red', 'blue', 'green'); $s2 = array('letters', 'a', 'b', 'c'); $s3 = 'foo'; $arr = array($s1, $s2, $s3); $o = Enumerator::assoc($arr, 'foo'); $this->assertEquals(null, $o); }