anchor.diff:    /// If you do decide to create your own text theme, consider using one of
     /// those predefined themes as a starting point for [copyWith] or [apply].
     const TextTheme({
  -    this.headline1,
  -    this.headline2,
  -    this.headline3,
  -    this.headline4,
  -    this.headline5,
  -    this.headline6,
  -    this.subtitle1,
  -    this.subtitle2,
  -    this.bodyText1,
  -    this.bodyText2,
  +    TextStyle? headline1,
  +    TextStyle? headline2,
  +    TextStyle? headline3,
  +    TextStyle? headline4,
  +    TextStyle? headline5,
  +    TextStyle? headline6,
  +    TextStyle? subtitle1,
  +    TextStyle? subtitle2,
  +    TextStyle? bodyText1,
  +    TextStyle? bodyText2,
       this.caption,
       this.button,
       this.overline,
  -  });
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is headline1. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? display4,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is headline2. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? display3,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is headline3. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? display2,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is headline4. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? display1,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is headline5. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? headline,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is headline6. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? title,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is subtitle1. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? subhead,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is subtitle2. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? subtitle,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is bodyText1. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? body2,
  +    @Deprecated(
  +      'This is the term used in the 2014 version of material design. The modern term is bodyText2. '
  +      'This feature was deprecated after v1.13.8.',
  +    )
  +    TextStyle? body1,
  +  }) : assert(
  +         (headline1 == null && headline2 == null && headline3 == null && headline4 == null && headline5 == null && headline6 == null &&
  +          subtitle1 == null && subtitle2 == null &&
  +          bodyText1 == null && bodyText2 == null) ||
  +         (display4 == null && display3 == null && display2 == null && display1 == null && headline == null && title == null &&
  +          subhead == null && subtitle == null &&
  +          body2 == null && body1 == null),
  +         'Cannot mix 2014 and 2018 terms in call to TextTheme() constructor.',
  +       ),
  +       headline1 = headline1 ?? display4,
  +       headline2 = headline2 ?? display3,
  +       headline3 = headline3 ?? display2,
  +       headline4 = headline4 ?? display1,
  +       headline5 = headline5 ?? headline,
  +       headline6 = headline6 ?? title,
  +       subtitle1 = subtitle1 ?? subhead,
  +       subtitle2 = subtitle2 ?? subtitle,
  +       bodyText1 = bodyText1 ?? body2,
  +       bodyText2 = bodyText2 ?? body1;
   
     /// Extremely large text.
     final TextStyle? headline1;
  
positive.code: /// bodyText1 and bodyText2.
  ///
  /// ![](https://storage.googleapis.com/spec-host-backup/mio-design%2Fassets%2F1W8kyGVruuG_O8psvyiOaCf1lLFIMzB-N%2Ftypesystem-typescale.png)
  ///
  /// The Material Design typography scheme was significantly changed in the
  /// current (2018) version of the specification
  
negative.code: /// ...where "light" is `FontWeight.w300`, "regular" is `FontWeight.w400` and
  /// "medium" is `FontWeight.w500`.
  ///
  /// The [TextTheme] API was originally based on the original material (2014)
  /// design spec, which used different text style names. For backwards
  /// compatibility's sake, this API continues to expose the old names. The table
  /// below should help with understanding the mapping of the API's old names and
  /// the new names (those in terms of the 2018 material specification).
  ///
  /// Each of the [TextTheme] text styles corresponds to one of the
  /// styles from 2018 spec. By default, the font sizes, font weights
  /// and letter spacings have not changed from their original,
  /// 2014, values.
  ///
  /// ```
  /// NAME       SIZE   WEIGHT   SPACING  2018 NAME
  /// display4   112.0  thin     0.0      headline1
  /// display3   56.0   normal   0.0      headline2
  /// display2   45.0   normal   0.0      headline3
  /// display1   34.0   normal   0.0      headline4
  /// headline   24.0   normal   0.0      headline5
  /// title      20.0   medium   0.0      headline6
  /// subhead    16.0   normal   0.0      subtitle1
  /// body2      14.0   medium   0.0      body1 (bodyText1)
  /// body1      14.0   normal   0.0      body2 (bodyText2)
  /// caption    12.0   normal   0.0      caption
  /// button     14.0   medium   0.0      button
  /// subtitle   14.0   medium   0.0      subtitle2
  /// overline   10.0   normal   0.0      overline
  /// ```
  ///
  /// Where "thin" is `FontWeight.w100`, "normal" is `FontWeight.w400` and
  /// "medium" is `FontWeight.w500`. Letter spacing for all of the original
  /// text styles was 0.0.
  ///
  /// The old names are deprecated in this API.
  ///
  /// Since the names `body1` and `body2` are used in both specifications but with
  /// different meanings, the API uses the terms `bodyText1` and `bodyText2` for
  /// the new API.
  ///
  /// To configure a [Theme] for the new sizes, weights, and letter spacings,
  /// initialize its [ThemeData.typography] value using [Typography.material2018].
  ///
  /// See also:
  ///
  