class HelloWorld
{
	public function sayHello(?int $a, ?int $b): void
	{
		
		if ($a === null && $b === null) {
			throw new \LogicException();
		}
		
		$this->foo($a !== null ? $a : $b); // error: Parameter #1 $c of method HelloWorld::foo() expects int, int|null given.  
	}
	
	public function foo(int $c){}
}