lerp method
Implementation
@override
ChartInsets lerp(ChartInsets next, double t) {
return ChartInsets(
left: ILengthValue.lerp(left, next.left, t),
top: ILengthValue.lerp(top, next.top, t),
right: ILengthValue.lerp(right, next.right, t),
bottom: ILengthValue.lerp(bottom, next.bottom, t),
);
}