/**
* This method returns the latter value should the former value evaluates
* to null.
*
* @access public
* @static
* @param IString\Type $xs the value to be evaluated
* @param IString\Type $ys the default value
* @return IString\Type the result
*/
public static function nvl(IString\Type $xs = null, IString\Type $ys = null) : IString\Type
{
return $xs ?? $ys ?? IString\Type::empty_();
}
/**
* This method tests the "empty" method.
*/
public function test_empty()
{
$p0 = IString\Type::empty_();
$this->assertInstanceOf('\\Saber\\Data\\IString\\Type', $p0);
$this->assertTrue(0 == strlen($p0->unbox()));
}
