public function testAssertValidKeysValidKeysEmpty() {
$options = array(
'testA' => 1,
'testB' => 2,
);
$valid = array(
'testA',
'testB',
'testC',
);
$expected = array(
'testA' => 1,
'testB' => 2,
'testC' => NULL,
);
$validated = PHPUnit_Util_XML::assertValidKeys($options, $valid);
$this
->assertEquals($expected, $validated);
}