code: public <R, W> JSONer register(Converter<R, W> converter, Class<?>... types) {
          for (Class<?> type : checkNotNull(types)) {
              typeConverts.put(type, checkNotNull(converter));
          }
          return this;
      }
docs: Register a class based JSON {@link GenericConverter} with given types
  
  @param property
  @param converter
  @return