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({
  -    TextStyle? headline1,
  -    TextStyle? headline2,
  -    TextStyle? headline3,
  -    TextStyle? headline4,
  -    TextStyle? headline5,
  -    TextStyle? headline6,
  -    TextStyle? subtitle1,
  -    TextStyle? subtitle2,
  -    TextStyle? bodyText1,
  -    TextStyle? bodyText2,
  +    this.headline1,
  +    this.headline2,
  +    this.headline3,
  +    this.headline4,
  +    this.headline5,
  +    this.headline6,
  +    this.subtitle1,
  +    this.subtitle2,
  +    this.bodyText1,
  +    this.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:   ///
    /// Typically used for captions or to introduce a (larger) headline.
    final TextStyle? overline;
  
    /// Extremely large text.
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [headline1].
    @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? get display4 => headline1;
  
    /// Very, very large text.
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [headline2].
    @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? get display3 => headline2;
  
    /// Very large text.
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [headline3].
    @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? get display2 => headline3;
  
    /// Large text.
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [headline4].
    @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? get display1 => headline4;
  
    /// Used for large text in dialogs.
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [headline5].
    @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? get headline => headline5;
  
    /// Used for the primary text in app bars and dialogs.
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [headline6].
    @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? get title => headline6;
  
    /// Used for the primary text in lists (e.g., [ListTile.title]).
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [subtitle1].
    @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? get subhead => subtitle1;
  
    /// For medium emphasis text that's a little smaller than [subhead].
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this [subtitle2].
    @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? get subtitle => subtitle2;
  
    /// Used for emphasizing text that would otherwise be [body1].
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this `body1`, and it is exposed in this API as
    /// [bodyText1].
    @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? get body2 => bodyText1;
  
    /// Used for the default text style for [Material].
    ///
    /// This was the name used in the material design 2014 specification. The new
    /// specification calls this `body2`, and it is exposed in this API as
    /// [bodyText2].
    @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? get body1 => bodyText2;
  
  
    /// Creates a copy of this text theme but with the given fields replaced with
    /// the new values.
  
negative.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
  