public function testWrappers()
{
$input = 'Ąbć dęfć';
$this->assertEquals(8, Str::len($input));
$this->assertEquals('dęfć', Str::sub($input, 4));
$this->assertEquals('bć dę', Str::sub($input, 1, 5));
// pos and related
$this->assertEquals(2, Str::pos($input, 'ć'));
$this->assertEquals(7, Str::pos($input, 'ć', 4));
$this->assertTrue(Str::contains($input, 'ć'));
$this->assertFalse(Str::contains($input, 'ź'));
$this->assertTrue(Str::startsWith($input, 'Ą'));
$this->assertTrue(Str::startsWith($input, 'Ąbć'));
$this->assertFalse(Str::startsWith($input, 'Abc'));
$this->assertTrue(Str::endsWith($input, 'ć'));
$this->assertTrue(Str::endsWith($input, 'ęfć'));
$this->assertFalse(Str::endsWith($input, 'f'));
// case-related
$this->assertEquals('ĄBĆ DĘFĆ', Str::upper($input));
$this->assertEquals('ąbć dęfć', Str::lower($input));
$this->assertEquals('Ąbć Dęfć', Str::ucwords($input));
$this->assertEquals('Ąć', Str::ucfirst('ąć'));
}