// FIXME There should be no duplicates, yet there are some
            return upgradedProperties.stream()
                .distinct()
                .collect(ImmutableList.toImmutableList());
        } catch (IOException e) {
            throw UncheckedException.throwAsUncheckedException(e);
        }
    }

    /**

   * ImmutableList}, in encounter order.
   *
   * @since 21.0
   */
  public static <E> Collector<E, ?, ImmutableList<E>> toImmutableList() {
    return CollectCollectors.toImmutableList();
  }

  /**
   * Returns the empty immutable list. This list behaves and performs comparably to {@link

   *
   * {@snippet :
   * @SuppressWarnings("unchecked") // safe because of ::isInstance check
   * ImmutableList<NewType> result =
   *     (ImmutableList) stream.filter(NewType.class::isInstance).collect(toImmutableList());
   * }
   */
  @SuppressWarnings("unchecked")
  @GwtIncompatible // Class.isInstance
  public static <T> Iterable<T> filter(Iterable<?> unfiltered, Class<T> desiredType) {
    checkNotNull(unfiltered);