fallback static method
      
ZeroAppBarStyle
fallback({ 
    
- Color? backgroundColor,
 - Color? foregroundColor,
 - TextStyle? titleStyle,
 - Brightness? statusBarBrightness,
 - double? titleSpacing,
 
A default value style of ZeroAppBarStyle
Implementation
static ZeroAppBarStyle fallback({
  Color? backgroundColor,
  Color? foregroundColor,
  TextStyle? titleStyle,
  Brightness? statusBarBrightness,
  double? titleSpacing,
}) =>
    ZeroAppBarStyle(
      backgroundColor: backgroundColor ?? ZeroColors.white,
      foregroundColor: foregroundColor ?? ZeroColors.black,
      titleStyle: titleStyle,
      statusBarBrightness: statusBarBrightness ?? Brightness.light,
      titleSpacing: titleSpacing,
    );