swapXY method
Copies this series swapping the XY pairs.
Implementation
ChartSeriesPair<C, Y, X, dynamic> swapXY() {
var seriesSwapped =
series.map((key, value) => MapEntry(key, swapListOfPairs(value)));
var copy = ChartSeriesPair<C, Y, X, dynamic>(seriesSwapped);
copy.xTitle = yTitle;
copy.yTitle = xTitle;
copy.title = title;
copy.colors = colors;
copy.disabledColors = disabledColors;
copy.options = options.copy();
return copy;
}