public function testIsString()
{
// from js
$this->assertTrue(__u::isString(join(', ', array(1, 2, 3))), 'strings are');
// extra
$this->assertFalse(__u::isString(1));
$this->assertTrue(__u::isString(''));
$this->assertTrue(__u::isString('1'));
$this->assertFalse(__u::isString(array()));
$this->assertFalse(__u::isString(null));
$this->assertFalse(__u(1)->isString());
$this->assertTrue(__u('1')->isString());
$this->assertTrue(__u('')->isString());
// docs
$this->assertTrue(__u::isString('moe'));
$this->assertTrue(__u::isString(''));
}