protected ActivationFile.Builder transformActivationFile_Missing(
                    Supplier<? extends ActivationFile.Builder> creator,
                    ActivationFile.Builder builder,
                    ActivationFile target) {
                String path = target.getMissing();
                String xformed = transformPath(path, target, "missing");

        builder.put(key, set);
        size += set.size();
      }
    }

    return new ImmutableSetMultimap<>(builder.buildOrThrow(), size, valueComparator);
  }

  /**
   * Returned by get() when a missing key is provided. Also holds the comparator, if any, used for
   * values.
   */
  private final transient ImmutableSet<V> emptySet;

  ImmutableSetMultimap(
      ImmutableMap<K, ImmutableSet<V>> map,

   * for (E e : occurrencesToRemove) {
   *   multisetToModify.remove(e);
   * }
   * }</pre>
   *
   * @return {@code true} if {@code multisetToModify} was changed as a result of this operation
   * @since 10.0 (missing in 18.0 when only the overload taking an {@code Iterable} was present)
   */
  @CanIgnoreReturnValue
  public static boolean removeOccurrences(
      Multiset<?> multisetToModify, Multiset<?> occurrencesToRemove) {

                    missingDescriptor(session, trace, a, (Exception) e.getCause());
                    if ((getPolicy(session, a, request) & ArtifactDescriptorPolicy.IGNORE_MISSING) != 0) {
                        return null;
                    }
                }
                result.addException(e);
                throw new ArtifactDescriptorException(result);
            }

        @Override
        protected ActivationFile.Builder transformActivationFile_Missing(
                Supplier<? extends ActivationFile.Builder> creator,
                ActivationFile.Builder builder,
                ActivationFile target) {
            stk.push(nextFrame("missing"));
            try {
                return super.transformActivationFile_Missing(creator, builder, target);
            } finally {
                stk.pop();

        resolutionErrorHandler.throwErrors(request, result);
        assertEquals(1, result.getArtifacts().size());

        //
        // Put in a bogus file to make sure missing files cause the resolution to fail.
        //
        file = new File(getBasedir(), "src/test/repository-system/maven-monkey-2.1.0.jar");
        assertFalse(file.exists());
        d.setSystemPath(file.getCanonicalPath());