Automattic / jetpack

		add_action( 'jetpack_sync_callable', $callable, 10, 2 );

		add_action( 'current_screen', array( $this, 'set_plugin_action_links' ), 9999 ); // Should happen very late.

		foreach ( self::ALWAYS_SEND_UPDATES_TO_THESE_OPTIONS as $option ) {

			add_action( "update_option_{$option}", array( $this, 'unlock_sync_callable' ) );

			add_action( "delete_option_{$option}", array( $this, 'unlock_sync_callable' ) );

		}

		foreach ( self::ALWAYS_SEND_UPDATES_TO_THESE_OPTIONS_NEXT_TICK as $option ) {

			add_action( "update_option_{$option}", array( $this, 'unlock_sync_callable_next_tick' ) );

			add_action( "delete_option_{$option}", array( $this, 'unlock_sync_callable' ) );

		}

		foreach ( self::ALWAYS_SEND_UPDATES_TO_THESE_OPTIONS_NEXT_TICK as $option ) {

			add_action( "update_option_{$option}", array( $this, 'unlock_sync_callable_next_tick' ) );

			add_action( "delete_option_{$option}", array( $this, 'unlock_sync_callable_next_tick' ) );

		}

		// Provide a hook so that hosts can send changes to certain callables right away.

		// Especially useful when a host uses constants to change home and siteurl.

		add_action( 'jetpack_sync_unlock_sync_callable', array( $this, 'unlock_sync_callable' ) );