anchor.diff:  String _stringFormatSuggestion<T>(T value) =>
       '$value'.replaceAll(' ', '').toLowerCase();
   
  -typedef StringSuggestionFilter(suggestion, String filterQuery);
  +typedef bool StringSuggestionFilter<T>(T suggestion, String filterQuery);
   
   /// The class is meant to be used in areas where a selection can be represented
   /// as a string.
  
positive.code: 
    /// Function for filtering a single suggestion/option, defaults to
    /// [filterOption] method.
    StringSuggestionFilter _suggestionFilter;
  
    /// The [ItemRenderer] that sanitizes options and queries before filtering.
    ItemRenderer _sanitizeString;
  
negative.code: 
    StringSelectionOptions.withOptionGroups(List<OptionGroup<T>> optionGroups,
        {ItemRenderer<T> toFilterableString,
        StringSuggestionFilter<T> suggestionFilter,
        ItemRenderer sanitizeString: _stringFormatSuggestion,
        bool shouldSort: false})
        : _toFilterableString = toFilterableString ??
  