src/vs/platform/instantiation/common/serviceCollection.ts/ServiceCollection/set
class ServiceCollection:	set<T>(id: ServiceIdentifier<T>, instanceOrDescriptor: T | SyncDescriptor<T>): T | SyncDescriptor<T> {
		const result = this._entries.get(id);
		this._entries.set(id, instanceOrDescriptor);
		return result;
	}