tree: toggleCollapsed returns boolean

src/vs/base/browser/ui/tree/abstractTree.ts

@@ -316,8 +316,8 @@ export abstract class AbstractTree<T, TFilterData, TRef> implements IDisposable
 		return this.model.setCollapsed(location, false, recursive);
 	}
 
-	toggleCollapsed(location: TRef, recursive: boolean = false): void {
-		this.model.setCollapsed(location, undefined, recursive);
+	toggleCollapsed(location: TRef, recursive: boolean = false): boolean {
+		return this.model.setCollapsed(location, undefined, recursive);
 	}
 
 	expandAll(): void {

src/vs/base/browser/ui/tree/asyncDataTree.ts

@@ -311,8 +311,8 @@ export class AsyncDataTree<T extends NonNullable<any>, TFilterData = void> imple
 		return true;
 	}
 
-	toggleCollapsed(element: T, recursive: boolean = false): void {
-		this.tree.toggleCollapsed(this.getDataNode(element), recursive);
+	toggleCollapsed(element: T, recursive: boolean = false): boolean {
+		return this.tree.toggleCollapsed(this.getDataNode(element), recursive);
 	}
 
 	expandAll(): void {