function getActualIndentationForListItemBeforeComma(commaToken, sourceFile, options) {
                // previous token is comma that separates items in list - find the previous item and try to derive indentation from it
                var commaItemInfo = ts.findListItemInfo(commaToken);
                if (commaItemInfo && commaItemInfo.listItemIndex > 0) {
                    return deriveActualIndentationFromList(commaItemInfo.list.getChildren(), commaItemInfo.listItemIndex - 1, sourceFile, options);
                }
                else {
                    // handle broken code gracefully
                    return -1 /* Unknown */;
                }
            }