protected override void visitStrategy(IFieldValidationStrategy strategy)
 {
     // attributes don't allow generics...
     strategy
         .As<MaximumStringLengthFieldStrategy>()
         .Length = Length;
 }
 protected override void visitStrategy(IFieldValidationStrategy strategy)
 {
     strategy
         .As<CollectionLengthValidationStrategy>()
         .Length = Length;
 }