// app (like the FrqUser class above), then the app's ClassLoader will never be gc'd. The reason
  // is that we attempt to run a thread in a separate ClassLoader that will detect when the FRQ
  // is no longer referenced, meaning that the app's ClassLoader has been gc'd, and when that
  // happens. But the thread's supposedly separate ClassLoader actually has a reference to the app's

   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where
   * doubling the table causes no thread to hash to it under
   * expanded mask.  We do not try to detect or remove such cells,
   * under the assumption that for long-running instances, observed
   * contention levels will recur, so the cells will eventually be
   * needed again; and for short-lived ones, it does not matter.
   */

                }
            }
            if (idx < tok.length) {
                qualifier = tok[idx++];
                fallback = isDigits(qualifier);
            }

            // string tokenizer won't detect these and ignores them
            if (part1.contains("..") || part1.startsWith(".") || part1.endsWith(".")) {
                fallback = true;
            }

            if (fallback) {

    try {
      new NullPointerTester().testInstanceMethods(instance, visibility);
    } catch (AssertionFailedError expected) {
      return;
    }
    fail("Should detect problem in " + instance.getClass().getSimpleName());
  }

  private static void shouldFail(Object instance) {
    shouldFail(instance, Visibility.PACKAGE);
    shouldFail(instance, Visibility.PROTECTED);

    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()
    //

import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingWrapperTester}. Live in a different package to detect reflection
 * access issues, if any.
 *
 * @author Ben Yu
 */
public class ForwardingWrapperTesterTest extends TestCase {

  private final ForwardingWrapperTester tester = new ForwardingWrapperTester();

   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where
   * doubling the table causes no thread to hash to it under
   * expanded mask.  We do not try to detect or remove such cells,
   * under the assumption that for long-running instances, observed
   * contention levels will recur, so the cells will eventually be
   * needed again; and for short-lived ones, it does not matter.
   */

    assertEquals("2", iterator.next());
    assertEquals("3", iterator.next());
    assertEquals("4", iterator.next());
    assertEquals(4, iterator.nextIndex());
    try {
      iterator.next();
      fail("did not detect end of list");
    } catch (NoSuchElementException expected) {
    }
    assertEquals(3, iterator.previousIndex());
    assertEquals("4", iterator.previous());
    assertEquals("3", iterator.previous());

   * of edges in a graph arranged to form a path (a sequence of adjacent outgoing edges) starting
   * and ending with the same node.
   *
   * <p>This method will detect any non-empty cycle, including self-loops (a cycle of length 1).
   */
  public static <N> boolean hasCycle(Graph<N> graph) {
    int numEdges = graph.edges().size();
    if (numEdges == 0) {

   * method blocks until {@code len} bytes of input data have been read into the array, or end of
   * file is detected. The number of bytes read is returned, possibly zero. Does not close the
   * stream.
   *
   * <p>A caller can detect EOF if the number of bytes read is less than {@code len}. All subsequent
   * calls on the same stream will return zero.
   *