anchor.diff:      extends JsonSerializer<Set<Date>>
     {
       @Override
  -    public void serialize( final Set<Date> dates,
  -                           final JsonGenerator generator,
  -                           final SerializerProvider provider )
  +    public void serialize( @javax.annotation.Nonnull final Set<Date> dates,
  +                           @javax.annotation.Nonnull final JsonGenerator generator,
  +                           @javax.annotation.Nonnull final SerializerProvider provider )
         throws IOException
       {
         generator.writeStartArray();
  
positive.code:   public static final class DateSetDeserializer
      extends JsonDeserializer<Set<Date>>
    {
      @Override
      public Set<Date> deserialize( final JsonParser parser, final DeserializationContext context )
        throws IOException
      {
        return deserializeCollection( parser, context, Set.class, new HashSet<Date>() );
  
negative.code:     }
    }
  
    @javax.annotation.Nonnull
    static DateFormat newDateFormatter()
    {
      return new SimpleDateFormat( "yyyy-MM-dd" );
    }
  
    @java.lang.SuppressWarnings( "deprecation" )
    @javax.annotation.Nonnull
    static <T extends Collection<Date>> T deserializeCollection( @javax.annotation.Nonnull final JsonParser parser,
                                                                 @javax.annotation.Nonnull final DeserializationContext context,
                                                                 @javax.annotation.Nonnull final Class<?> type,
                                                                 @javax.annotation.Nonnull final T result )
      throws IOException
    {
      if ( !parser.isExpectedStartArrayToken() )
  