SomeUncheckedException sue = new SomeUncheckedException();
    IllegalArgumentException iae = new IllegalArgumentException(sue);
    RuntimeException re = new RuntimeException(iae);
    IllegalStateException ex = new IllegalStateException(re);

    assertEquals(asList(ex, re, iae, sue), Throwables.getCausalChain(ex));
    assertSame(sue, Iterables.getOnlyElement(Throwables.getCausalChain(sue)));

    SomeUncheckedException sue = new SomeUncheckedException();
    IllegalArgumentException iae = new IllegalArgumentException(sue);
    RuntimeException re = new RuntimeException(iae);
    IllegalStateException ex = new IllegalStateException(re);

    assertEquals(asList(ex, re, iae, sue), Throwables.getCausalChain(ex));
    assertSame(sue, Iterables.getOnlyElement(Throwables.getCausalChain(sue)));

    // (We're relying on callers to call this method only with an edge that's in the graph.)
    return requireNonNull(outEdgeMap.get(edge));
  }

  @Override
  public N removeInEdge(E edge, boolean isSelfLoop) {
    if (isSelfLoop) {
      checkNonNegative(--selfLoopCount);
    }
    N previousNode = inEdgeMap.remove(edge);

      int j = findNextJ();
      if (j == -1) {
        nextPermutation = null;
        return;
      }
      /*
       * requireNonNull is safe because we don't clear nextPermutation until we're done calling this
       * method.
       */
      requireNonNull(nextPermutation);

      int l = findNextL(j);
      Collections.swap(nextPermutation, j, l);
      int n = nextPermutation.size();

        return;
      }
    }
    // Execute the runnable immediately. Because of scheduling this may end up getting called before
    // some of the previously added runnables, but we're OK with that. If we want to change the
    // contract to guarantee ordering among runnables we'd have to modify the logic here to allow
    // it.
    executeListener(runnable, executor);
  }

  /**

  // TODO: Test getQueueLength().
  // TODO: Test hasQueuedThreads().
  // TODO: Test getWaitQueueLength(Guard).
  // TODO: Test automatic signaling before leave, waitFor, and reentrant enterWhen.
  // TODO: Test blocking to re-enter monitor after being signaled.
  // TODO: Test interrupts with both interruptible and uninterruptible monitor.
  // TODO: Test multiple waiters: If guard is still satisfied, signal next waiter.

   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other `equals()` expression
   *       involving {@code view} will throw)
   *   <li>{@code hashCode()} does not throw
   *   <li>if {@code node} is re-added to the graph after having been removed, {@code view}'s
   *       behavior is undefined
   * </ul>
   *
   * @throws IllegalArgumentException if {@code node} is not an element of this graph
   */
  @Override

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Useful suppliers.
 *
 * <p>All methods return serializable suppliers as long as they're given serializable parameters.
 *
 * @author Laurence Gonsalves
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Suppliers {

/**
 * Utilities for treating interruptible operations as uninterruptible. In all cases, if a thread is
 * interrupted during such a call, the call continues to block until the result is available or the
 * timeout elapses, and only then re-interrupts the thread.
 *
 * @author Anthony Zana
 * @since 10.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Uninterruptibles {

    try {
      Class.forName(unsafeComparatorClassName());
      return true;
    } catch (Error | ClassNotFoundException tolerable) {
      /*
       * We're probably running on Android.
       *
       * A note on exception types:
       *
       * Android API level 10 throws ExceptionInInitializerError the first time and
       * ClassNotFoundException thereafter.