if (o.isPresent()) {
                had++;
                items.addAll(o.get());
            }
        }
        return had == 0 ? Optional.empty() : Optional.of(List.copyOf(items));
    }

    protected Optional<Map<String, String>> collectMapIfPresentOrEmpty(
            Function<O, Optional<Map<String, String>>> getter) {
        int had = 0;

 *   <li>Implementations can be generally assumed to prioritize memory efficiency, then speed of
 *       access, and lastly speed of creation.
 *   <li>The {@code copyOf} methods will sometimes recognize that the actual copy operation is
 *       unnecessary; for example, {@code copyOf(copyOf(anArrayList))} should copy the data only
 *       once. This reduces the expense of habitually making defensive copies at API boundaries.

  @Before
  public void createSets() {
    wrappedSet = new HashSet<>();
    wrappedSet.add(1);
    wrappedSet.add(2);
    wrappedSet.add(3);

    copyOfWrappedSet = ImmutableSet.copyOf(wrappedSet);
    setToTest =
        InvalidatableSet.of(wrappedSet, () -> wrappedSet.contains(1), () -> 1 + "is not present");
  }

  @Test
  @SuppressWarnings("TruthSelfEquals")
  public void testEquals() {

   */
  public static <E> ImmutableSortedSet<E> copyOf(
      Comparator<? super E> comparator, Collection<? extends E> elements) {
    return copyOf(comparator, (Iterable<? extends E>) elements);
  }

  /**
   * Returns an immutable sorted set containing the elements of a sorted set, sorted by the same
   * {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which always uses the

   * {@link Collection}, this method behaves exactly as {@link #copyOf(Collection)}; otherwise, it
   * behaves exactly as {@code copyOf(elements.iterator()}.
   *
   * @throws NullPointerException if {@code elements} contains a null element
   */
  public static <E> ImmutableList<E> copyOf(Iterable<? extends E> elements) {
    checkNotNull(elements); // TODO(kevinb): is this here only for GWT?

    COPY_OF_COLLECTION {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys);
      }
    },
    COPY_OF_ITERATOR {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys.iterator());
      }
    },
    BUILDER_ADD_ENTRY_BY_ENTRY {
      @Override

     */
    protected EditBody createEditBody(final FileConfig entity) {
        final EditBody body = new EditBody();
        copyBeanToBean(entity, body, copyOp -> {
            copyOp.excludeNull();
            copyOp.exclude(Constants.PERMISSIONS, Constants.VIRTUAL_HOSTS);
        });
        final PermissionHelper permissionHelper = ComponentUtil.getPermissionHelper();

        builder.put(entry.getKey(), entry.getValue());
      }
      return ImmutableMap.copyOf(builder);
    }
  }

  public static class ImmutableMapCopyOfEntriesGenerator extends TestStringMapGenerator {
    @Override
    protected Map<String, String> create(Entry<String, String>[] entries) {
      return ImmutableMap.copyOf(asList(entries));
    }
  }

  public static class ImmutableMapUnhashableValuesGenerator

  }

  private static void testReverse(char[] input, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Chars.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(char[] input, int fromIndex, int toIndex, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Chars.reverse(input, fromIndex, toIndex);

    ImmutableListMultimap<String, Integer> multimap = ImmutableListMultimap.copyOf(input);
    new EqualsTester().addEqualityGroup(input, multimap).testEquals();
  }

  public void testCopyOfEmpty() {
    ArrayListMultimap<String, Integer> input = ArrayListMultimap.create();
    ImmutableListMultimap<String, Integer> multimap = ImmutableListMultimap.copyOf(input);
    new EqualsTester().addEqualityGroup(input, multimap).testEquals();
  }