public function testRtrim()
{
$t = new \Test\Strings();
$this->assertSame($t->testRtrim(' hello '), ' hello');
$this->assertSame($t->testRtrim('hello '), 'hello');
$this->assertSame($t->testRtrim(' hello'), ' hello');
$this->assertSame($t->testRtrim2Params('Hello World', 'Hdle'), 'Hello Wor');
}