src/vs/workbench/contrib/callHierarchy/browser/callHierarchyPeek.ts/CallHierarchyTreePeekWidget/updateDirection
class CallHierarchyTreePeekWidget:	async updateDirection(newDirection: CallHierarchyDirection): Promise<void> {
		const model = this._tree.getInput();
		if (model && newDirection !== this._direction) {
			this._treeViewStates.set(this._direction, this._tree.getViewState());
			this._direction = newDirection;
			await this.showModel(model);
		}
	}