In case if data parsed to treegrid are not sorted by levels, then indendations draws by treegrid is not good. Sample is there: https://snippet.dhtmlx.com/3yof7w8j
We have tree -> Africa -> Angola -> Sample Region -> Sample City
but Angola, Sample Region and Sample City have equals indendations, because in dataset are in reverse order.
If I provide correct order of dataset, then indentations are correct: https://snippet.dhtmlx.com/6btejgzt