}
    try {
      unmod.compute(4, (k, v) -> v);
      fail("UnsupportedOperationException expected");
    } catch (UnsupportedOperationException expected) {
    }
    try {
      unmod.merge(4, "four", (k, v) -> v);
      fail("UnsupportedOperationException expected");
    } catch (UnsupportedOperationException expected) {
    }
    try {
      unmod.clear();

    checkArgument(columnIndex != null, "Column %s not in %s", columnKey, columnList);
    return set(rowIndex, columnIndex, value);
  }

  /*
   * TODO(jlevy): Consider creating a merge() method, similar to putAll() but
   * copying non-null values only.
   */

  /**
   * {@inheritDoc}
   *
   * <p>If {@code table} is an {@code ArrayTable}, its null values will be stored in this table,

import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;

// TODO(cpovirk): Should this be merged into UninterruptiblesTest?
/**
 * Unit test for {@link Uninterruptibles#getUninterruptibly}
 *
 * @author Kevin Bourrillion
 * @author Chris Povirk
 */
public class UninterruptibleFutureTest extends TestCase {

    if (iterable instanceof Collection) {
      return ((Collection<?>) iterable).isEmpty();
    }
    return !iterable.iterator().hasNext();
  }

  /**
   * Returns an iterable over the merged contents of all given {@code iterables}. Equivalent entries
   * will not be de-duplicated.
   *
   * <p>Callers must ensure that the source {@code iterables} are in non-descending order as this

   * keys and values are the result of applying the provided mapping functions to the input
   * elements.
   *
   * <p>If the mapped keys contain duplicates (according to the comparator), the values are merged
   * using the specified merging function. Entries will appear in the encounter order of the first
   * occurrence of the key.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */

   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  @CheckForNull
  public final V merge(
      K key, V value, BiFunction<? super V, ? super V, ? extends @Nullable V> function) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the map unmodified.

    checkArgument(columnIndex != null, "Column %s not in %s", columnKey, columnList);
    return set(rowIndex, columnIndex, value);
  }

  /*
   * TODO(jlevy): Consider creating a merge() method, similar to putAll() but
   * copying non-null values only.
   */

  /**
   * {@inheritDoc}
   *
   * <p>If {@code table} is an {@code ArrayTable}, its null values will be stored in this table,

    checkNotNull(key);
    checkNotNull(function);
    return compute(key, (k, oldValue) -> (oldValue == null) ? null : function.apply(k, oldValue));
  }

  @Override
  @CheckForNull
  public V merge(
      K key, V newValue, BiFunction<? super V, ? super V, ? extends @Nullable V> function) {
    checkNotNull(key);
    checkNotNull(newValue);
    checkNotNull(function);
    return compute(

  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private interface Merger {

    ListenableFuture<List<String>> merged(ListenableFuture<String> a, ListenableFuture<String> b);

    Merger allMerger =
        new Merger() {
          @Override
          public ListenableFuture<List<String>> merged(
              ListenableFuture<String> a, ListenableFuture<String> b) {

   * `new TypeParameter<@Nullable T>() {}` and have it act as a plain `TypeParameter<T>`, but
   * hopefully no one would do that, anyway. See also the comment on TypeParameter itself.
   *
   * TODO(cpovirk): Elaborate on this / merge with other comment?
   */
  public final <X> TypeToken<T> where(TypeParameter<X> typeParam, TypeToken<X> typeArg) {
    TypeResolver resolver =
        new TypeResolver()
            .where(