src/vs/workbench/contrib/extensions/browser/extensionsActions.ts/ToggleSyncExtensionAction/constructor
class ToggleSyncExtensionAction:	constructor(
		@IConfigurationService private readonly configurationService: IConfigurationService,
		@IExtensionsWorkbenchService private readonly extensionsWorkbenchService: IExtensionsWorkbenchService,
		@IUserDataSyncEnablementService private readonly userDataSyncEnablementService: IUserDataSyncEnablementService,
		@IInstantiationService instantiationService: IInstantiationService,
	) {
		super('extensions.sync', '', ToggleSyncExtensionAction.SYNC_CLASS, false, instantiationService);
		this._register(Event.filter(this.configurationService.onDidChangeConfiguration, e => e.affectedKeys.includes('settingsSync.ignoredExtensions'))(() => this.update()));
		this._register(userDataSyncEnablementService.onDidChangeEnablement(() => this.update()));
		this.update();
	}