apply method
Implementation
TextTheme apply(TextTheme original, {TextStyle? inputStyle}) {
return original.copyWith(
headline1: header1,
headline2: header2,
headline3: header3,
headline4: header4,
headline5: body1Bold,
headline6: body2Bold,
subtitle1: (inputStyle ?? body1Medium),
subtitle2: body2Medium,
bodyText1: body1Normal,
bodyText2: body2Normal,
caption: body3Light,
button: body1Medium,
overline: body3Light,
);
}