default:
        return new RegularImmutableAsList<E>(this, toArray());
    }
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  Object @Nullable [] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */

/**
 * Implementation of ImmutableMap backed by a JDK HashMap, which has smartness protecting against
 * hash flooding.
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableMap<K, V> extends ImmutableMap<K, V> {
  /**
   * Creates an {@code ImmutableMap} backed by a JDK HashMap. Used when probable hash flooding is

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.DoNotCall;
import java.util.Map;
import javax.annotation.CheckForNull;

/**
 * A type-to-instance map backed by an {@link ImmutableMap}. See also {@link
 * MutableTypeToInstanceMap}.
 *
 * @author Ben Yu
 * @since 13.0
 */
@ElementTypesAreNonnullByDefault

import java.util.EnumMap;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@code BiMap} backed by an {@code EnumMap} instance for keys-to-values, and a {@code HashMap}
 * instance for values-to-keys. Null keys are not permitted, but null values are. An {@code
 * EnumHashBiMap} and its inverse are both serializable.
 *

   * calling thread. Tasks are run to completion before a {@code Future} is returned to the caller
   * (unless the executor has been shutdown).
   *
   * <p>The returned executor is backed by the executor returned by {@link
   * MoreExecutors#newDirectExecutorService} and subject to the same constraints.
   *
   * <p>Although all tasks are immediately executed in the thread that submitted the task, this

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.EnumMap;
import java.util.Map;

/**
 * A {@code BiMap} backed by two {@code EnumMap} instances. Null keys and values are not permitted.
 * An {@code EnumBiMap} and its inverse are both serializable.
 *
 * <p>See the Guava User Guide article on <a href=

import com.google.common.collect.testing.SampleElements.Unhashables;
import com.google.common.collect.testing.UnhashableObject;
import java.util.Map;

@GwtIncompatible // GWT's ImmutableMap emulation is backed by java.util.HashMap.
public class RegularImmutableMapWithUnhashableValuesMapInterfaceTest
    extends AbstractImmutableMapMapInterfaceTest<Integer, UnhashableObject> {
  @Override

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import java.io.Serializable;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/** A regex pattern implementation which is backed by the {@link Pattern}. */
@ElementTypesAreNonnullByDefault
@GwtIncompatible
final class JdkPattern extends CommonPattern implements Serializable {
  private final Pattern pattern;

  JdkPattern(Pattern pattern) {

 * limitations under the License.
 */

package com.google.common.graph;

import java.util.Set;

/**
 * A class to allow {@link Graph} implementations to be backed by a {@link BaseGraph}. This is not
 * currently planned to be released as a general-purpose forwarding class.
 *
 * @author James Sexton
 */
@ElementTypesAreNonnullByDefault

 * limitations under the License.
 */

package com.google.common.graph;

import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * A class to allow {@link Network} implementations to be backed by a provided delegate. This is not
 * currently planned to be released as a general-purpose forwarding class.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 */
@ElementTypesAreNonnullByDefault