merge method

Implementation

ZeroButtonGroupStyleSet merge(ZeroButtonGroupStyleSet? other) {
  if (other == null) return this;

  return copyWith(
    filled: filled?.merge(other.filled) ?? other.filled,
    outlined: outlined?.merge(other.outlined) ?? other.outlined,
    text: text?.merge(other.text) ?? other.text,
    underline: underline?.merge(other.underline) ?? other.underline,
  );
}