src/vs/workbench/api/common/extHostTreeViews.ts/ExtHostTreeView/resolveUnknownParentChain
class ExtHostTreeView:	private resolveUnknownParentChain(element: T): Promise<TreeNode[]> {
		return this.resolveParent(element)
			.then((parent) => {
				if (!parent) {
					return Promise.resolve([]);
				}
				return this.resolveUnknownParentChain(parent)
					.then(result => this.resolveTreeNode(parent, result[result.length - 1])
						.then(parentNode => {
							result.push(parentNode);
							return result;
						}));
			});
	}