@GwtIncompatible
  @J2ktIncompatible
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    int distinctElements = stream.readInt();
    setBackingMap(new LinkedHashMap<E, Count>());
    Serialization.populateMultiset(this, stream, distinctElements);
  }

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

  @GwtIncompatible
  @J2ktIncompatible
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
    stream.defaultReadObject();
    int distinctElements = stream.readInt();
    setBackingMap(new HashMap<>());
    Serialization.populateMultiset(this, stream, distinctElements);
  }

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

    checkArgument(backingMap.isEmpty());
    this.backingMap = backingMap;
  }

  /** Used during deserialization only. The backing map must be empty. */
  void setBackingMap(Map<E, Count> backingMap) {
    this.backingMap = backingMap;
  }

  // Required Implementations

  /**
   * {@inheritDoc}
   *