src/vs/workbench/services/extensionManagement/common/extensionManagementService.ts/ExtensionManagementService/installVSIX
class ExtensionManagementService:	async installVSIX(vsix: URI, manifest: IExtensionManifest, options?: InstallVSIXOptions): Promise<ILocalExtension> {
		const serversToInstall = this.getServersToInstall(manifest);
		if (serversToInstall?.length) {
			await this.checkForWorkspaceTrust(manifest);
			const [local] = await Promises.settled(serversToInstall.map(server => this.installVSIXInServer(vsix, server, options)));
			return local;
		}
		return Promise.reject('No Servers to Install');
	}