function getDataItemValue(dataItem) {
  return isObject(dataItem) && !isArray(dataItem) && !(dataItem instanceof Date) ? dataItem.value : dataItem;
}
The method do not ensure performance.
data could be [12, 2323, {value: 223}, [1221, 23], {value: [2, 23]}]
This helper method retieves value from data.