}

  @Override
  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;

  }

  @Override
  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;

    return proxyClass.isInstance(arg)
        // Equal proxy instances should mostly be instance of proxyClass
        // Under some edge cases (such as the proxy of JDK types serialized and then deserialized)
        // the proxy type may not be the same.
        // We first check isProxyClass() so that the common case of comparing with non-proxy objects
        // is efficient.

  @CheckForNull
  public final V remove(@CheckForNull Object rowKey, @CheckForNull Object columnKey) {
    throw new UnsupportedOperationException();
  }

  /**
   * Serialized type for all ImmutableTable instances. It captures the logical contents and
   * preserves iteration order of all views.
   */
  static final class SerializedForm implements Serializable {

  @SuppressWarnings("unchecked")
  static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  // This reference is only used by GWT compiler to infer the keys and values
  // of the map that needs to be serialized.
  private @Nullable Comparator<? super K> unusedComparatorForSerialization;
  private @Nullable K unusedKeyForSerialization;
  private @Nullable V unusedValueForSerialization;

  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  @CheckForNull
  public final V forcePut(K key, V value) {
    throw new UnsupportedOperationException();
  }

  /**
   * Serialized type for all ImmutableBiMap instances. It captures the logical contents and they are
   * reconstructed using public factory methods. This ensures that the implementation types remain
   * as implementation details.
   *

  /**
   * As described in <a href="http://www.ietf.org/rfc/rfc3902.txt">RFC 3902</a>, this constant
   * ({@code application/soap+xml}) is used to identify SOAP 1.2 message envelopes that have been
   * serialized with XML 1.0.
   *
   * <p>For SOAP 1.1 messages, see {@code XML_UTF_8} per <a
   * href="http://www.w3.org/TR/2000/NOTE-SOAP-20000508/">W3C Note on Simple Object Access Protocol
   * (SOAP) 1.1</a>
   *