* allocation—not that any program should be deserializing hostile inputs to begin with!)
     */
    setDelegates(new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new HashMap<V, K>());
    Serialization.populateMap(this, stream);
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

    valueTypeOrObjectUnderJ2cl = (Class<V>) requireNonNull(stream.readObject());
    setDelegates(
        new EnumMap<K, V>(keyTypeOrObjectUnderJ2cl), new EnumMap<V, K>(valueTypeOrObjectUnderJ2cl));
    Serialization.populateMap(this, stream);
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

    stream.defaultReadObject();
    int size = Serialization.readCount(stream);
    init(16); // resist hostile attempts to allocate gratuitous heap
    Serialization.populateMap(this, stream, size);
  }

  // TODO(cpovirk): Should we have a serialVersionUID here?