protected function parse_pagination() {

		if ( $this->args['items_per_page'] == - 1 ) {
			return null;
		}

		if ( $this->args['page'] < 1 ) {
			throw new \InvalidArgumentException( "page parameter must be at least 1." );
		}

		$per_page = absint( $this->args['items_per_page'] );
		$page     = absint( $this->args['page'] );

		$count  = $per_page;
		$offset = $per_page * ( $page - 1 );

		return new Limit( $count, $offset );
	}