* Returns the platform preferred map implementation that preserves insertion order when used only
   * for insertions.
   */
  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> preservesInsertionOrderOnPutsMap() {
    return new LinkedHashMap<>();
  }

  /**
   * Returns the platform preferred map implementation that preserves insertion order when used only

    }

    Map<K, ImmutableCollection.Builder<V>> ensureBuilderMapNonNull() {
      Map<K, ImmutableCollection.Builder<V>> result = builderMap;
      if (result == null) {
        result = Platform.preservesInsertionOrderOnPutsMap();
        builderMap = result;
      }
      return result;
    }

    ImmutableCollection.Builder<V> newValueCollectionBuilderWithExpectedSize(int expectedSize) {