// TODO(fry): empirically optimize this
  static final int DRAIN_MAX = 16;

  // Fields

  static final Logger logger = Logger.getLogger(LocalCache.class.getName());

  /**
   * Mask value for indexing into segments. The upper bits of a key's hash code are used to choose
   * the segment.
   */
  final int segmentMask;

  /**

  enum State {
    /** The {@link CloseableList} has not been subsumed or closed. */
    OPEN,

    /**
     * The {@link CloseableList} has been subsumed into another. It may not be closed or subsumed
     * into any other.
     */
    SUBSUMED,

    /**
     * Some {@link ListenableFuture} has a callback attached that will close the {@link

      checkEntryNotNull(key, value);
      enumMap.put(key, value);
    }
    return ImmutableEnumMap.asImmutable(enumMap);
  }

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements. The
   * resulting implementation is specialized for enum key types. The returned map and its views will

  // TODO(fry): empirically optimize this
  static final int DRAIN_MAX = 16;

  // Fields

  static final Logger logger = Logger.getLogger(LocalCache.class.getName());

  /**
   * Mask value for indexing into segments. The upper bits of a key's hash code are used to choose
   * the segment.
   */
  final int segmentMask;

  /**