*/

  public static <V extends @Nullable Object> ListenableFuture<V> catching(
      ListenableFuture<? extends V> input,
      Class<Throwable> exceptionType,
      Function<? super Throwable, ? extends V> fallback,
      Executor executor) {
    return AbstractCatchingFuture.create(input, exceptionType, fallback, executor);
  }

  public static <V extends @Nullable Object> ListenableFuture<V> catchingAsync(

  /** Resolver for resolving parameter and field types with {@link #runtimeType} as context. */
  @LazyInit private transient @Nullable TypeResolver invariantTypeResolver;

  /** Resolver for resolving covariant types with {@link #runtimeType} as context. */
  @LazyInit private transient @Nullable TypeResolver covariantTypeResolver;

  /**
   * Constructs a new type token of {@code T}.
   *

import com.google.common.primitives.Ints;
import com.google.errorprone.annotations.concurrent.LazyInit;
import com.google.j2objc.annotations.WeakOuter;
import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableMultiset} with zero or more elements.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible

  }

  @Override
  public @Nullable Entry<E> firstEntry() {
    return isEmpty() ? null : getEntry(0);
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return isEmpty() ? null : getEntry(length - 1);
  }

  @Override
  public int count(@Nullable Object element) {
    int index = elementSet.indexOf(element);

 */
@GwtCompatible
public abstract class AbstractSequentialIterator<T> extends UnmodifiableIterator<T> {
  private @Nullable T nextOrNull;

  /**
   * Creates a new iterator with the given first element, or, if {@code firstOrNull} is null,
   * creates a new empty iterator.
   */
  protected AbstractSequentialIterator(@Nullable T firstOrNull) {
    this.nextOrNull = firstOrNull;
  }

  /**

  }

  @GwtIncompatible // not present in emulated superclass
  @Override
  int copyIntoArray(@Nullable Object[] dst, int offset) {
    return delegateList.copyIntoArray(dst, offset);
  }

  @Override
  @Nullable Object @Nullable [] internalArray() {
    return delegateList.internalArray();
  }

  @Override
  int internalArrayStart() {

import java.util.ListIterator;
import org.jspecify.annotations.Nullable;

/**
 * An iterator that transforms a backing list iterator; for internal use. This avoids the object
 * overhead of constructing a {@link Function} for internal methods.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class TransformedListIterator<F extends @Nullable Object, T extends @Nullable Object>

import java.util.ListIterator;
import org.jspecify.annotations.Nullable;

/**
 * An iterator that transforms a backing list iterator; for internal use. This avoids the object
 * overhead of constructing a {@link Function} for internal methods.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class TransformedListIterator<F extends @Nullable Object, T extends @Nullable Object>

  private static final @Nullable Object jla = getJla();

  /**
   * The "getStackTraceElementMethod" method, only available on some JDKs so we use reflection to
   * find it when available. When this is null, use the slow way.
   */
  @J2ktIncompatible @GwtIncompatible // java.lang.reflect
  private static final @Nullable Method getStackTraceElementMethod =

import java.util.List;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A container class for the five sample elements we need for testing.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public class SampleElements<E extends @Nullable Object> implements Iterable<E> {
  // TODO: rename e3, e4 => missing1, missing2
  private final E e0;