lerp method
Implementation
BarItem lerp(BarItem endValue, double t) {
return BarItem(
radius: BorderRadius.lerp(
radius, endValue is BarItemOptions ? endValue.radius : null, t),
gradient: Gradient.lerp(
gradient, endValue is BarItemOptions ? endValue.gradient : null, t),
border: BorderSide.lerp(border,
endValue is BarItemOptions ? (endValue.border) : BorderSide.none, t),
color: Color.lerp(color, endValue.color, t),
);
}