function prepare_items() {
		$this->columns = array(
			$this->get_columns(),
			$this->get_hidden_columns(),
			$this->get_sortable_columns()
		);

		$this->items = $this->get_items();

		usort($this->example_data, array($this, 'usort_reorder'));

		//paging
		//$per_page = $this->get_items_per_page('books_per_page', 5);
		//$current_page = $this->get_pagenum();
	}