merge method
Implementation
ZeroDatePickerStyle merge(ZeroDatePickerStyle? other) {
if (other == null) return this;
return copyWith(
headerBackgroundColor: other.headerBackgroundColor,
pickerBackgroundColor: other.pickerBackgroundColor,
entryModeIconColor: other.entryModeIconColor,
helpTextStyle: other.helpTextStyle,
dateTextStyle: other.dateTextStyle,
shape: other.shape,
textfieldStyle: other.textfieldStyle,
elevation: other.elevation,
insetPadding: other.insetPadding,
calendarStyle: other.calendarStyle,
);
}