Fixed TS typings

Author: Vlad Balin

dist/index.js.map

@@ -38,7 +38,7 @@ export declare class Collection<R extends Record = Record> extends Transactional
     _onChildrenChange(record: R, options?: TransactionOptions, initiator?: Transactional): void;
     get(objOrId: string | R | Object): R;
     each(iteratee: (val: R, key: number) => void, context?: any): void;
-    forEach(iteratee: (val: R, key: number) => void, context?: any): void;
+    forEach(iteratee: (val: R, key?: number) => void, context?: any): void;
     every(iteratee: Predicate<R>, context?: any): boolean;
     filter(iteratee: Predicate<R>, context?: any): R[];
     find(iteratee: Predicate<R>, context?: any): R;

lib/collection/index.d.ts

@@ -191,7 +191,7 @@ export class Collection< R extends Record = Record> extends Transactional implem
         }
     }
 
-    forEach( iteratee : ( val : R, key : number ) => void, context? : any ){
+    forEach( iteratee : ( val : R, key? : number ) => void, context? : any ){
         return this.each( iteratee, context );
     }