public function getSortNext()
	{
		$defaultSort = $this->grid->getColumnDefaultSort($this->key);

		if ($this->sort == 'ASC') {
			return [$this->key => $defaultSort === 'DESC' ? FALSE : 'DESC'];
		} else if ($this->sort == 'DESC') {
			return [$this->key => $defaultSort === 'DESC' ? 'ASC' : FALSE];
		}

		return [$this->key => 'ASC'];
	}