How to display the exact x value provided to FlSpot in SideTitles?

I need to display the exact x values that I've provided to `spots`, but when I get the value in `getTitlesWidget` it is different from the original data. Actually, I don't want the `interval` changes the value. Is it possible with fl_chart?
By the way, thanks for the awesome package!
```
...
bottomTitles: AxisTitles(
sideTitles: SideTitles(
showTitles: true,
reservedSize: 20,
interval: 600,
getTitlesWidget: (value, meta) {
final dateFormat = intl.DateFormat("H");
return Text(
dateFormat.format(
ViewHelper()
.convertTimeStampToDate(value.toInt()),
),
);
},
),
),
...
```

Start with the SideTitles and getTitlesWidget behavior shown in the issue, reproducing it with interval set to 600 and the supplied spots. Trace how the callback value is generated and determine whether exact x values can be displayed without interval altering them. Done means the requested values are preserved and the behavior is covered by an appropriate chart test.

Written by the indexing model from the issue text.