public function testRule($options, $value, $expectedResult, $useEncoding)
{
if ($useEncoding && !function_exists('mb_strtolower')) {
$this->markTestSkipped('mbstring extension not enabled');
}
$rule = new ToLowerRule($options);
$filter = new ToLower();
$result = $filter->apply($rule, $value);
$this->assertEquals($expectedResult, $result);
}