public static CombinedValidatorBuilder <T> Append <T>(this CombinedValidatorBuilder <T> b, string itemId, IValidator <T> validator)
 {
     b.Add(new ItemIdAdapterValidator <T>(itemId, validator));
     return(b);
 }
 public static CombinedValidatorBuilder <T> Append <T, P>(this CombinedValidatorBuilder <T> b, string itemId, Func <T, P> propertyGetter, IValidator <P> validator)
 {
     b.Add(CreateAdapter(itemId, propertyGetter, validator));
     return(b);
 }
 public static CombinedValidatorBuilder <T> Append <T>(this CombinedValidatorBuilder <T> b, IValidator <T> validator)
 {
     b.Add(validator);
     return(b);
 }