public ListStringConverter(ConverterMappingHints mappingHints = default) :
     base(c => TextConcatenator.Concatenate(c),
          c => new List <string>(TextConcatenator.Split(c)),
          mappingHints)
 {
 }
 public ObservableStringCollectionConverter(ConverterMappingHints mappingHints = default) :
     base(c => TextConcatenator.Concatenate(c),
          c => new ObservableCollection <string>(TextConcatenator.Split(c)),
          mappingHints)
 {
 }