AnsPress_Upgrader::__construct()

	private function __construct() {
		$this->check_tables();
		// Enable required addons.
		ap_activate_addon( 'tag.php' );
		ap_activate_addon( 'category.php' );
		ap_activate_addon( 'reputation.php' );

		// Disable sending email while upgrading.
		define( 'AP_DISABLE_EMAIL', true );

		// Also disable inserting of reputations and notifications.
		define( 'AP_DISABLE_INSERT_NOTI', true );

		$this->check_old_meta_table_exists();
		$this->get_question_ids();

		foreach ( (array) $this->question_ids as $id ) {
			// translators: %s is question ID.
			echo esc_attr( "\n\r" . sprintf( __( 'Migrating question: %d', 'anspress-question-answer' ), $id ) . "\n\r" );
			$this->question_tasks( $id );
		}

		$this->migrate_reputations();
		$this->migrate_category_data();
	}