src/vs/workbench/contrib/extensions/browser/extensionsActions.ts/InstallSpecificVersionOfExtensionAction/install
class InstallSpecificVersionOfExtensionAction:	private install(extension: IExtension, version: string): Promise<void> {
		return this.instantiationService.createInstance(SearchExtensionsAction, '@installed ').run()
			.then(() => {
				return this.extensionsWorkbenchService.installVersion(extension, version)
					.then(extension => {
						const requireReload = !(extension.local && this.extensionService.canAddExtension(toExtensionDescription(extension.local)));
						const message = requireReload ? localize('InstallAnotherVersionExtensionAction.successReload', "Please reload Visual Studio Code to complete installing the extension {0}.", extension.identifier.id)
							: localize('InstallAnotherVersionExtensionAction.success', "Installing the extension {0} is completed.", extension.identifier.id);
						const actions = requireReload ? [{
							label: localize('InstallAnotherVersionExtensionAction.reloadNow', "Reload Now"),
							run: () => this.hostService.reload()
						}] : [];
						this.notificationService.prompt(
							Severity.Info,
							message,
							actions,
							{ sticky: true }
						);
					}, error => this.notificationService.error(error));
			});
	}