src/vs/workbench/services/extensions/common/extensionHostManager.ts/LazyStartExtensionHostManager/start
class LazyStartExtensionHostManager:	public async start(allExtensions: IExtensionDescription[], myExtensions: ExtensionIdentifier[]): Promise<void> {
		if (myExtensions.length > 0) {
			// there are actual extensions, so let's launch the extension host
			const actual = this._createActual(`contains ${myExtensions.length} extension(s): ${myExtensions.map(extId => extId.value)}.`);
			const result = actual.start(allExtensions, myExtensions);
			this._startCalled.open();
			return result;
		}
		// there are no actual extensions running, store extensions in `this._lazyStartExtensions`
		this._lazyStartExtensions = new ExtensionHostExtensions();
		this._lazyStartExtensions.set(allExtensions, myExtensions);
		this._startCalled.open();
	}