Another exception was thrown: NoSuchMethodError: The method '>' was called on null.

[ZahidTekbas]

I have a trouble with the package. Sometimes, it says "Another exception was thrown: NoSuchMethodError: The method '>' was called on null" and it does not print any chart. Is there a way to solve that or to detect which method causes error?

edit: it could be related to this error:
══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
The following NoSuchMethodError was thrown during paint():
The method 'toDouble' was called on null.
Receiver: null
Tried calling: toDouble()

The relevant error-causing widget was:
CustomPaint
CustomPaint:file:///Users/mac13/Developer/flutter/.pub-cache/hosted/pub.dartlang.org/k_chart-0.4.0/lib/k_chart_widget.dart:194:11

[mafanwei]

Thank you for your feedback.
mScrollX = (details.primaryDelta! / mScaleX + mScrollX) .clamp(0.0, ChartPainter.maxScrollX) .toDouble();
primaryDelta may be null. If the [GestureDragUpdateCallback] is for a two-dimensional drag (e.g., a pan), then this value is null.
I will fix this bug.

[mafanwei]

done. See 0.4.1.