public boolean isEmpty() {
    return delegateCollection().isEmpty();
  }

  @Override
  boolean isPartialView() {
    return delegateCollection().isPartialView();
  }

  /** Serialized form that leads to the same performance as the original list. */
  @GwtIncompatible // serialization
  @J2ktIncompatible
  static class SerializedForm implements Serializable {
    final ImmutableCollection<?> collection;

  public boolean isEmpty() {
    return delegateCollection().isEmpty();
  }

  @Override
  boolean isPartialView() {
    return delegateCollection().isPartialView();
  }

  /** Serialized form that leads to the same performance as the original list. */
  @GwtIncompatible // serialization
  @J2ktIncompatible
  static class SerializedForm implements Serializable {
    final ImmutableCollection<?> collection;