Stacked Bar Chart not working properly?

I'm really confused, **how** and **when** does `stringForValue` actually work?

I thought I knew how it is being called but I guess I don't.

I'm trying to combine data into one **stacked** bar if the x-axis values are the same, but I'm confused on when `stringForValue` is called to format the x-axis labels.

This is currently what I'm seeing:


I was **somewhat** able to combine the data from the date label `08/06/17` because there's 2 data for that x-axis date (as can be seen in the table below), but the upper red part should be `5.66`, not `8.66`. Somehow, it is adding `3.00` to `5.66` to make `8.66`.

However, that's not what I'm concerned about. I'm trying to eliminate the first blank `08/06/17` x-axis label, but for some reason, `stringForValue` is being called for each index.

Here's a bit of my code:

```
extension ServiceChargeViewController: IAxisValueFormatter
{
func stringForValue(_ value: Double, axis: AxisBase?) -> String
{
let tempServiceRecord_ARRAY = serviceRecord_ARRAY.sorted(by: {$0.date < $1.date})

print("value = \(value)")

let date = tempServiceRecord_ARRAY[Int(value)].date

print("date = \(date)")

return ReusableClass.typeThreeDateFormat(date: date)
}
}

func createBarChart(dataPoints: [Date], values: [Double])
{
var dataEntries: [BarChartDataEntry] = []

....

for lastIndex in 0..

Start by tracing IAxisValueFormatter.stringForValue and BarChartDataEntry through the chart axis-labeling path, then reproduce the provided dataPoints, values, and x values in createBarChart. Determine why the formatter receives 0, 1, 2, 3, 4 instead of the entry positions, and verify that the repeated 08/06/17 label is eliminated without breaking stacked bars.

Written by the indexing model from the issue text.