public function sort(array $query, $key, $label, $url = null) 
	{
		Argument::i()
			->test(2, 'string')
			->test(3, 'string')
			->test(4, 'string', 'null');
			
		$block = Sort::i($query, $key, $label);
		
		if($url) {
			$block->setUrl($url);
		}
		
		return $block;
	}