public function test_arrays_have_same_keys_and_values()
 {
     $this->assertTrue(question_utils::arrays_have_same_keys_and_values(array(), array()));
     $this->assertTrue(question_utils::arrays_have_same_keys_and_values(array('key' => 1), array('key' => '1')));
     $this->assertFalse(question_utils::arrays_have_same_keys_and_values(array(), array('key' => 1)));
     $this->assertFalse(question_utils::arrays_have_same_keys_and_values(array('key' => 2), array('key' => 1)));
     $this->assertFalse(question_utils::arrays_have_same_keys_and_values(array('key' => 1), array('otherkey' => 1)));
     $this->assertFalse(question_utils::arrays_have_same_keys_and_values(array('sub0' => '2', 'sub1' => '2', 'sub2' => '3', 'sub3' => '1'), array('sub0' => '1', 'sub1' => '2', 'sub2' => '3', 'sub3' => '1')));
 }