import java.util.concurrent.Callable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *

import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Comparator;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** An ordering that tries several comparators in order. */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
final class CompoundOrdering<T extends @Nullable Object> extends Ordering<T>

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Preconditions;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible(serializable = true, emulated = true)

 */

package com.google.common.collect;

import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A class that implements {@code Comparable} without generics, such as those found in libraries
 * that support Java 1.4 and before. Our library needs to do the bare minimum to accommodate such

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.List;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A list multimap which forwards all its method calls to another list multimap. Subclasses should
 * override one or more methods to modify the behavior of the backing multimap as desired per the <a

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import java.util.SortedSet;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A sorted set multimap which forwards all its method calls to another sorted set multimap.
 * Subclasses should override one or more methods to modify the behavior of the backing multimap as

package com.google.common.util.concurrent;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Preconditions;
import java.util.concurrent.Executor;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link ListenableFuture} which forwards all its method calls to another future. Subclasses
 * should override one or more methods to modify the behavior of the backing future as desired per

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.DoNotMock;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An iterator that supports a one-element lookahead while iterating.
 *
 * <p>See the Guava User Guide article on <a href=

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.annotations.VisibleForTesting;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of {@link ImmutableList} backed by a simple array.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(serializable = true, emulated = true)

 * limitations under the License.
 */

package com.google.common.collect;

import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * GWT implementation of {@link ImmutableSet} that forwards to another {@code Set} implementation.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault