* the iterator is created, in any way except through the iterator's own remove method, the
   * iterator will generally throw a {@link ConcurrentModificationException}. Thus, in the face of
   * concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary,
   * non-deterministic behavior at an undetermined time in the future.
   *

        //
        // Note that there is a race condition here which can result in missing
        // a cyclic edge: it's possible for two threads to simultaneous find
        // "safe" edges which together form a cycle. Preventing this race
        // condition efficiently without _introducing_ deadlock is probably
        // tricky. For now, just accept the race condition---missing a warning

            requests.add(new MetadataRequest(metadata, null, REPOSITORY_CONTEXT).setTrace(trace));

            for (RemoteRepository repository : request.getRepositories()) {
                requests.add(new MetadataRequest(metadata, repository, REPOSITORY_CONTEXT).setTrace(trace));
            }
        }

        // initial try, use locally cached metadata

            RequestTrace trace,
            RepositorySystem resolver,
            RemoteRepositoryManager remoteRepositoryManager,
            List<RemoteRepository> repositories,
            ProjectBuildingRequest.RepositoryMerging repositoryMerging,
            ReactorModelPool modelPool,
            Map<String, Object> parentCache) {
        this.session = session;
        this.trace = trace;
        this.resolver = resolver;

    return stringWriter.toString();
  }

  /**
   * Returns the stack trace of {@code throwable}, possibly providing slower iteration over the full
   * trace but faster iteration over parts of the trace. Here, "slower" and "faster" are defined in
   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()

    return stringWriter.toString();
  }

  /**
   * Returns the stack trace of {@code throwable}, possibly providing slower iteration over the full
   * trace but faster iteration over parts of the trace. Here, "slower" and "faster" are defined in
   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()

        if (finishImmediately) {
            projectBuildFutureTask.run();
        }
        return projectBuildFutureTask;
    }

    public Future<ProjectSegment> take() throws InterruptedException {
        return null;
    }

    public Future<ProjectSegment> poll() {
        return null;
    }

      // we allow one second worth of work to go in a burst (i.e. take less than a second)
      assertTrue(burst <= 1000);
      long afterBurst = measureTotalTimeMillis(limiter, oneSecWorthOfWork, new Random());
      // but work beyond that must take at least one second
      assertTrue(afterBurst >= 1000);
    }
  }

  /**

   * on the fields of TimeoutFuture. This field is slightly different from the fields discussed
   * there: cancel() never reads this field, only writes to it. That makes the race here completely
   * harmless, rather than just 99.99% harmless.
   */
  @CheckForNull @LazyInit private List<@Nullable Present<V>> values;

  CollectionFuture(

   * detected. This implementation may replace the entries in entryArray with its own entry objects
   * (though they will have the same key/value contents), and will take ownership of entryArray.
   */
  static <K, V> ImmutableMap<K, V> create(
      int n, @Nullable Entry<K, V>[] entryArray, boolean throwIfDuplicateKeys) {
    Map<K, V> delegateMap = Maps.newHashMapWithExpectedSize(n);