src/vs/workbench/browser/parts/views/treeView.ts/TreeDataSource/getChildren
class TreeDataSource:	async getChildren(element: ITreeItem): Promise<ITreeItem[]> {
		let result: ITreeItem[] = [];
		if (this.treeView.dataProvider) {
			try {
				result = (await this.withProgress(this.treeView.dataProvider.getChildren(element))) ?? [];
			} catch (e) {
				if (!(<string>e.message).startsWith('Bad progress location:')) {
					throw e;
				}
			}
		}
		return result;
	}