Function isDataItemOption

src/util/model.ts:162–167

(dataItem: OptionDataItem)

 * This helper method determine if dataItem has extra option besides value
 */
export function isDataItemOption(dataItem: OptionDataItem): boolean {
    return isObject(dataItem)
        && !(dataItem instanceof Array);
        // // markLine data can be array
        // && !(dataItem[0] && isObject(dataItem[0]) && !(dataItem[0] instanceof Array));
}

// Compatible with previous definition: id could be number (but not recommended).
// number and string are treated the same when compared.