src/vs/workbench/api/common/extHostTreeViews.ts/ExtHostTreeViews/createExtHostTreeView
class ExtHostTreeViews:	private createExtHostTreeView<T>(id: string, options: vscode.TreeViewOptions<T>, extension: IExtensionDescription): ExtHostTreeView<T> {
		const treeView = new ExtHostTreeView<T>(id, options, this._proxy, this.commands.converter, this.logService, extension);
		this.treeViews.set(id, treeView);
		return treeView;
	}