public void remove() {
      checkForConcurrentModification();
      checkState(current != null, "no calls to next() since the last call to remove()");
      if (current != next) { // after call to next()
        previous = current.previous;
        nextIndex--;
      } else { // after call to previous()
        next = current.next;
      }
      removeNode(current);
      current = null;
      expectedModCount = modCount;

   * <ul>
   *   <li>{@code required}, {@code from}, and {@code to} should all be indexes into {@code array};
   *   <li>{@code required} should be in the range [{@code from}, {@code to}];
   *   <li>all the values with indexes in the range [0, {@code from}) should be less than or equal
   *       to all the values with indexes in the range [{@code from}, {@code to}];

   * iterable supports it. Note that it is <i>not</i> possible to delete the last skipped element by
   * immediately calling {@code remove()} on that iterator, as the {@code Iterator} contract states
   * that a call to {@code remove()} before a call to {@code next()} will throw an {@link
   * IllegalStateException}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#skip}
   *
   * @since 3.0
   */

    @Override
    public final T call() {
      try {
        return realCall();
      } catch (Throwable t) {
        threadUnexpectedException(t);
        return null;
      }
    }
  }

  public abstract class CheckedInterruptedCallable<T> implements Callable<T> {
    protected abstract T realCall() throws Throwable;

    @Override
    public final T call() {
      try {

 * associated with a key and then add the key back to the multimap, that key will come last in the
 * key iteration order.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *

 *
 * <p>{@code RuntimeException}s thrown by tasks are simply logged and the executor keeps trucking.
 * If an {@code Error} is thrown, the error will propagate and execution will stop until it is
 * restarted by a call to {@link #execute}.
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class SequentialExecutor implements Executor {

    final Exception e = new Exception();
    TrustedListenableFutureTask<Integer> task =
        TrustedListenableFutureTask.create(
            new Callable<Integer>() {
              @Override
              public Integer call() throws Exception {
                throw e;
              }
            });
    task.run();
    assertTrue(task.isDone());
    assertFalse(task.isCancelled());
    try {
      getDone(task);
      fail();

   * inserted into the multiset must be <i>mutually comparable</i> by the specified comparator:
   * {@code comparator.compare(e1, e2)} must not throw a {@code ClassCastException} for any elements
   * {@code e1} and {@code e2} in the multiset. If the user attempts to add an element to the
   * multiset that violates this constraint, the {@code add(Object)} call will throw a {@code
   * ClassCastException}.

  /**
   * Returns an instance of {@code interfaceType} that delegates all method calls to the {@code
   * target} object, enforcing the specified time limit on each call. This time-limited delegation
   * is also performed for calls to {@link Object#equals}, {@link Object#hashCode}, and {@link
   * Object#toString}.
   *
   * <p>If the target method call finishes before the limit is reached, the return value or

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

/**
 * A TimeLimiter implementation which actually does not attempt to limit time at all. This may be
 * desirable to use in some unit tests. More importantly, attempting to debug a call which is
 * time-limited would be extremely annoying, so this gives you a time-limiter you can easily swap in
 * for your real time-limiter while you're debugging.
 *