docs: @Post("/projects/{projectName}/repos/{repoName}/preview")
      public CompletableFuture<Iterable<ChangeDto<?>>> preview(
              @Param("revision") @Default("-1") String revision,
              Repository repository,
              @RequestConverter(ChangesRequestConverter.class) Iterable<Change<?>> changes) {
  
          final CompletableFuture<Map<String, Change<?>>> changesFuture =
                  repository.previewDiff(new Revision(revision), changes);
  
          return changesFuture.thenApply(previewDiffs -> previewDiffs.values().stream()
                                                                     .map(DtoConverter::convert)
                                                                     .collect(toImmutableList()));
      }