diff --git a/build.gradle b/build.gradle
--- a/build.gradle
+++ b/build.gradle
@@ -56,7 +56,7 @@ typescript {
         
         if(symbols != 'none') {
             sourceMap = true
-            sourceRoot = packageName
+            sourceRoot = "pack:${packageName}"
         }
 
         if (flavour == 'node') {
diff --git a/src/main/ts/Uuid.ts b/src/main/ts/Uuid.ts
--- a/src/main/ts/Uuid.ts
+++ b/src/main/ts/Uuid.ts
@@ -14,6 +14,10 @@ declare const Buffer: any;
 
 const _window: any = "undefined" !== typeof window ? window : null;
 
+function noop(): never {
+    throw new Error();
+}
+
 interface WritableArrayLike<T> {
     length: number;
     [n: number]: T;
@@ -24,13 +28,13 @@ interface WritableArrayLike<T> {
 // detect to determine the best RNG source, normalizing to a function
 // that
 // returns 128-bits of randomness, since that's what's usually required
-let _rng: () => WritableArrayLike<number> = () => [];
+let _rng: () => WritableArrayLike<number> = noop;
 
 function setupBrowser() {
     // Allow for MSIE11 msCrypto
     const _crypto = _window.crypto || _window.msCrypto;
 
-    if (!_rng && _crypto && _crypto.getRandomValues) {
+    if (_rng === noop && _crypto && _crypto.getRandomValues) {
         // WHATWG crypto-based RNG - http://wiki.whatwg.org/wiki/Crypto
         //
         // Moderately fast, high quality
@@ -44,7 +48,7 @@ function setupBrowser() {
         } catch (e) { /**/ }
     }
 
-    if (!_rng) {
+    if (_rng === noop) {
         // Math.random()-based (RNG)
         //
         // If all else fails, use Math.random(). It's fast, but is of
diff --git a/src/main/ts/di/Container.ts b/src/main/ts/di/Container.ts
--- a/src/main/ts/di/Container.ts
+++ b/src/main/ts/di/Container.ts
@@ -5,7 +5,7 @@ import { ServiceMap, Descriptor, Partial
 import { TraceSource } from "../log/TraceSource";
 import { Configuration, RegistrationMap } from "./Configuration";
 import { Cancellation } from "../Cancellation";
-import { IDestroyable, ICancellation } from "../interfaces";
+import { ICancellation } from "../interfaces";
 import { isDescriptor } from "./traits";
 import { LifetimeManager } from "./LifetimeManager";
 import { each, isString } from "../safe";
@@ -14,7 +14,7 @@ import { FluentConfiguration } from "./f
 
 const trace = TraceSource.get("@implab/core/di/ActivationContext");
 
-export class Container<S extends object = any> implements ServiceContainer<S>, IDestroyable {
+export class Container<S extends object = any> implements ServiceContainer<S> {
     readonly _services: ContainerServiceMap<S>;
 
     readonly _lifetimeManager: LifetimeManager;
@@ -29,10 +29,11 @@ export class Container<S extends object 
 
     constructor(parent?: Container<S>) {
         this._parent = parent;
-        this._services = parent ? Object.create(parent._services) : {};
+        this._services = Object.create(parent ? parent._services : null);
         this._cleanup = [];
         this._root = parent ? parent.getRootContainer() : this;
         this._services.container = new ValueDescriptor(this) as any;
+        this._services.childContainer = { activate: () => this.createChildContainer() };
         this._disposed = false;
         this._lifetimeManager = new LifetimeManager();
     }
diff --git a/src/main/ts/di/interfaces.ts b/src/main/ts/di/interfaces.ts
--- a/src/main/ts/di/interfaces.ts
+++ b/src/main/ts/di/interfaces.ts
@@ -1,3 +1,4 @@
+import { IDestroyable } from "../interfaces";
 import { ActivationContext } from "./ActivationContext";
 import { LifetimeManager } from "./LifetimeManager";
 
@@ -27,7 +28,7 @@ export interface ServiceLocator<S extend
     resolve<K extends ContainerKeys<S>>(name: K, def?: TypeOfService<S, K>): TypeOfService<S, K>;
 }
 
-export interface ServiceContainer<S extends object> extends ServiceLocator<S> {
+export interface ServiceContainer<S extends object> extends ServiceLocator<S>, IDestroyable {
     getLifetimeManager(): LifetimeManager;
     register<K extends keyof S>(name: K, service: Descriptor<S, S[K]>): this;
     register(services: PartialServiceMap<S>): this;
@@ -37,6 +38,8 @@ export interface ServiceContainer<S exte
 
 export interface ContainerProvided<S extends object> {
     container: ServiceLocator<S>;
+
+    childContainer: ServiceContainer<S>;
 }
 
 export type ContainerRegistered<S extends object> = /*{
diff --git a/src/test/ts/tests/TextTests.ts b/src/test/ts/tests/TextTests.ts
--- a/src/test/ts/tests/TextTests.ts
+++ b/src/test/ts/tests/TextTests.ts
@@ -2,6 +2,7 @@ import { StringBuilder } from "../text/S
 import { test } from "./TestTraits";
 import { MockConsole } from "../mock/MockConsole";
 import { ConsoleWriter } from "../log/ConsoleWriter";
+import { Uuid } from "../Uuid";
 
 test("String builder", async t => {
     const sb = new StringBuilder();
@@ -84,3 +85,11 @@ test("ConsoleWriter", t => {
     t.deepEqual(mockConsole.getBuffer()[0].data, ["25 or 6 to 4! Let's have some ", { product: "tee" }], "Should handle many text chunks and object at the end");
 
 });
+
+test("Uuid test", (t, log) => {
+    const id = Uuid();
+    log.log("uuid = {0}", id);
+    t.assert(id, "Should generate uuid");
+    t.notEqual(id, Uuid(), "uuid should never match");
+
+});