anchor.diff:      value = 37 * value + fontFamily.hashCode;
       value = 37 * value + fontSize.hashCode;
       value = 37 * value + fontWeight.hashCode;
  +    value = 37 * value + fontStyle.hashCode;
       value = 37 * value + textAlign.hashCode;
       value = 37 * value + textBaseline.hashCode;
       value = 37 * value + decoration.hashCode;
  
positive.code:     String fontFamily,
      double fontSize,
      FontWeight fontWeight,
      TextAlign textAlign,
      TextBaseline textBaseline,
      double height,
  
negative.code:   final String fontFamily;
    final double fontSize; // in pixels
    final FontWeight fontWeight;
    final FontStyle fontStyle;
    final TextAlign textAlign;
    final TextBaseline textBaseline;
    final double height; // multiple of fontSize
  