code: public static <E> Set<E> setify(ObjectMapper mapper, Object source, Class<E> targetElementType) {
          return (Set<E>) collectify(mapper, source, Set.class, targetElementType);
      }
docs: Convert an object to a set.
  
  @param mapper            the object mapper
  @param source            the source object
  @param targetElementType the target set element type
  @return set