src/vs/workbench/api/common/extHostQuickOpen.ts/ExtHostQuickPick/_fireDidChangeSelection
class ExtHostQuickPick:		_fireDidChangeSelection(handles: number[]) {
			const items = coalesce(handles.map(handle => this._handlesToItems.get(handle)));
			this._selectedItems = items;
			this._onDidChangeSelectionEmitter.fire(items);
		}