diff --git a/src/vs/base/common/objects.ts b/src/vs/base/common/objects.ts
index a463a8e7c10fcf13fa71957eee8f42fc22bfc6f6..ab5c34250cb25901a40c567d5ebb25e1e0fd2649 100644
--- a/src/vs/base/common/objects.ts
+++ b/src/vs/base/common/objects.ts
@@ -120,10 +120,6 @@ export function assign(destination: any, ...sources: any[]): any {
 	return destination;
 }
 
-export function toObject<T>(arr: T[], keyMap: (t: T) => string): { [key: string]: T } {
-	return arr.reduce((o, d) => assign(o, { [keyMap(d)]: d }), Object.create(null));
-}
-
 export function equals(one: any, other: any): boolean {
 	if (one === other) {
 		return true;
diff --git a/src/vs/platform/instantiation/common/descriptors.ts b/src/vs/platform/instantiation/common/descriptors.ts
index 46cda3ca9860ef409957dea2cd811155b9b398af..3dcea1588d4c683b66d84f0d91c978724c4a5303 100644
--- a/src/vs/platform/instantiation/common/descriptors.ts
+++ b/src/vs/platform/instantiation/common/descriptors.ts
@@ -4,51 +4,17 @@
  *--------------------------------------------------------------------------------------------*/
 'use strict';
 
-import { illegalArgument } from 'vs/base/common/errors';
 import * as instantiation from './instantiation';
 
-export class AbstractDescriptor<T> {
 
-	constructor(private _staticArguments: any[]) {
-		// empty
-	}
-
-	public appendStaticArguments(more: any[]): void {
-		this._staticArguments.push.apply(this._staticArguments, more);
-	}
+export class SyncDescriptor<T> {
 
-	public staticArguments(): any[];
-	public staticArguments(nth: number): any;
-	public staticArguments(nth?: number): any[] {
-		if (isNaN(nth)) {
-			return this._staticArguments.slice(0);
-		} else {
-			return this._staticArguments[nth];
-		}
-	}
+	readonly ctor: any;
+	readonly staticArguments: any[];
 
-	_validate(type: T): void {
-		if (!type) {
-			throw illegalArgument('can not be falsy');
-		}
-	}
-}
-
-export class SyncDescriptor<T> extends AbstractDescriptor<T> {
-
-	constructor(private _ctor: any, ...staticArguments: any[]) {
-		super(staticArguments);
-	}
-
-	public get ctor(): any {
-		return this._ctor;
-	}
-
-	protected bind(...moreStaticArguments: any[]): SyncDescriptor<T> {
-		let allArgs: any[] = [];
-		allArgs = allArgs.concat(this.staticArguments());
-		allArgs = allArgs.concat(moreStaticArguments);
-		return new SyncDescriptor<T>(this._ctor, ...allArgs);
+	constructor(ctor: new (...args: any[]) => T, ..._staticArguments: any[]) {
+		this.ctor = ctor;
+		this.staticArguments = _staticArguments;
 	}
 }
 
@@ -175,4 +141,4 @@ export interface SyncDescriptor8<A1, A2, A3, A4, A5, A6, A7, A8, T> {
 	bind(a1: A1, a2: A2, a3: A3, a4: A4, a5: A5, a6: A6): SyncDescriptor2<A7, A8, T>;
 	bind(a1: A1, a2: A2, a3: A3, a4: A4, a5: A5, a6: A6, a7: A7): SyncDescriptor1<A8, T>;
 	bind(a1: A1, a2: A2, a3: A3, a4: A4, a5: A5, a6: A6, a7: A7, a8: A8): SyncDescriptor0<T>;
-}
\ No newline at end of file
+}
diff --git a/src/vs/platform/instantiation/common/instantiationService.ts b/src/vs/platform/instantiation/common/instantiationService.ts
index 052e2eba90a55df3ea0d142f8837def7394c12e1..19618c36a72394abe89bb7d34d0e5777e48ab28a 100644
--- a/src/vs/platform/instantiation/common/instantiationService.ts
+++ b/src/vs/platform/instantiation/common/instantiationService.ts
@@ -77,7 +77,7 @@ export class InstantiationService implements IInstantiationService {
 	private _createInstance<T>(desc: SyncDescriptor<T>, args: any[]): T {
 
 		// arguments given by createInstance-call and/or the descriptor
-		let staticArgs = desc.staticArguments().concat(args);
+		let staticArgs = desc.staticArguments.concat(args);
 
 		// arguments defined by service decorators
 		let serviceDependencies = _util.getServiceDependencies(desc.ctor).sort((a, b) => a.index - b.index);
@@ -117,9 +117,7 @@ export class InstantiationService implements IInstantiationService {
 		argArray.push(...staticArgs);
 		argArray.push(...serviceArgs);
 
-		const instance = create.apply(null, argArray);
-		desc._validate(instance);
-		return <T>instance;
+		return <T>create.apply(null, argArray);
 	}
 
 	private _getOrCreateServiceInstance<T>(id: ServiceIdentifier<T>): T {