message: cascadable walk() method
diff: @@ -59,6 +59,7 @@ namespace MakerJs.model {
  *
  * @param modelToOriginate The model to originate.
  * @param origin Optional offset reference point.
  + * @returns The original model (for cascading).
  */
  export function originate(modelToOriginate: IModel, origin?: IPoint) {
  @@ -351,6 +352,7 @@ namespace MakerJs.model {
  * @param pathCallback Callback for each path.
  * @param modelCallbackBeforeWalk Callback for each model prior to recursion, which can cancel the recursion if it returns false.
  * @param modelCallbackAfterWalk Callback for each model after recursion.
  + * @returns The original model (for cascading).
  */
  export function walk(modelContext: IModel, options: IWalkOptions) {
  @@ -412,6 +414,7 @@ namespace MakerJs.model {
  walkRecursive(modelContext, modelContext.layer, [0, 0], [], '');
  + return modelContext;
  }
  /**
  