anchor.diff:  import 'package:flutter/widgets.dart';
   
   import 'button.dart';
  -import 'colors.dart';
   import 'floating_action_button_theme.dart';
   import 'scaffold.dart';
   import 'theme.dart';
  
positive.code:   Widget build(BuildContext context) {
      final ThemeData theme = Theme.of(context);
      final FloatingActionButtonThemeData floatingActionButtonTheme = theme.floatingActionButtonTheme;
  
      // Applications should no longer use accentIconTheme's color to configure
      // the foreground color of floating action buttons. For more information, see
      // https://flutter.dev/go/remove-fab-accent-theme-dependency.
      if (this.foregroundColor == null && floatingActionButtonTheme.foregroundColor == null) {
        final bool accentIsDark = theme.accentColorBrightness == Brightness.dark;
        final Color defaultAccentIconThemeColor = accentIsDark ? Colors.white : Colors.black;
        if (theme.accentIconTheme.color != defaultAccentIconThemeColor) {
          debugPrint(
            'Warning: '
            'The support for configuring the foreground color of '
            'FloatingActionButtons using ThemeData.accentIconTheme '
            'has been deprecated. Please use ThemeData.floatingActionButtonTheme '
            'instead. See '
            'https://flutter.dev/go/remove-fab-accent-theme-dependency. '
            'This feature was deprecated after v1.13.2.'
          );
        }
      }
  
      final Color foregroundColor = this.foregroundColor
        ?? floatingActionButtonTheme.foregroundColor
  
negative.code:   /// [ThemeData.floatingActionButtonTheme] is used. If that property is also
    /// null, then the [ColorScheme.onSecondary] color of [ThemeData.colorScheme]
    /// is used.
    final Color? foregroundColor;
  
    /// The button's background color.
  