return importModel;
    }

    private static <T> T cache(
            ModelCache cache, String groupId, String artifactId, String version, String tag, Callable<T> supplier) {
        Supplier<T> s = asSupplier(supplier);
        if (cache == null) {
            return s.get();
        } else {
            return cache.computeIfAbsent(groupId, artifactId, version, tag, s);
        }
    }

  /** Number of (unsynchronized) retries in the containsValue method. */
  static final int CONTAINS_VALUE_RETRIES = 3;

  /**
   * Number of cache access operations that can be buffered per segment before the cache's recency
   * ordering information is updated. This is used to avoid lock contention by recording a memento

  }

  @Override
  public ImmutableSortedMap<K, V> descendingMap() {
    // TODO(kevinb): The descendingMap is never actually cached at all. Either:
    //
    // - Cache it, and annotate the field with @LazyInit.
    // - Simplify the code below, and consider eliminating the field (b/287198172), which is also
    //   set by one of the constructors.

  }

  @Override
  public ImmutableSortedMap<K, V> descendingMap() {
    // TODO(kevinb): The descendingMap is never actually cached at all. Either:
    //
    // - Cache it, and annotate the field with @LazyInit.
    // - Simplify the code below, and consider eliminating the field (b/287198172), which is also
    //   set by one of the constructors.

 * by the garbage collector. Entries with reclaimed keys or values may be removed from the cache on
 * each cache modification, on occasional cache accesses, or on calls to {@link Cache#cleanUp}; such
 * entries may be counted in {@link Cache#size}, but will never be visible to read or write
 * operations.
 *

        }

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