code: public ExceptionalStream<T, E> distinct() {
          final Set<Object> set = new HashSet<>();
  
          return filter(new Try.Predicate<T, E>() {
              @Override
              public boolean test(T value) {
                  return set.add(hashKey(value));
              }
          });
      }
docs: Distinct and filter by occurrences.
  
  @param occurrencesFilter
  @return