merge method
Implementation
ZeroTabBarStyle merge(ZeroTabBarStyle? other) {
if (other == null) return this;
return copyWith(
backgroundColor: other.backgroundColor,
activeColor: other.activeColor,
inactiveColor: other.inactiveColor,
indicatorColor: other.indicatorColor,
padding: other.padding,
labelPadding: other.labelPadding,
iconSize: other.iconSize,
labelStyle: labelStyle?.merge(other.labelStyle) ?? other.labelStyle,
isScrollable: other.isScrollable,
);
}