*
   * But the methods in this class want to throw different exceptions, depending on the args, so it
   * appears that this pattern is not directly applicable. But we can use the ridiculous, devious
   * trick of throwing an exception in the middle of the construction of another exception. Hotspot
   * is fine with that.
   */

  /**

      ReferenceQueue<Object> queue,
      PhantomReference<Object> frqReference) {
    this.queue = queue;

    this.finalizableReferenceClassReference = new WeakReference<>(finalizableReferenceClass);

    // Keep track of the FRQ that started us so we know when to stop.
    this.frqReference = frqReference;
  }

  /** Loops continuously, pulling references off the queue and cleaning them up. */

  @VisibleForTesting @CheckForNull transient @Nullable Object[] elements;

  /**
   * Keeps track of metadata like the number of hash table bits and modifications of this data
   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note
   * that we choose not to make this volatile, so we do less of a "best effort" to track such
   * errors, for better performance.
   */
  private transient int metadata;

  int recursionCount;

  private static final Object duh = new Object();

  @Param Mode mode;

  enum Mode {
    LAZY_STACK_TRACE {
      @Override
      List<StackTraceElement> getStackTrace(Throwable t) {
        return lazyStackTrace(t);
      }
    },
    GET_STACK_TRACE {
      @Override
      List<StackTraceElement> getStackTrace(Throwable t) {
        return asList(t.getStackTrace());
      }
    };

    @CheckForNull private Iterator<? extends T> toRemove;

    /* The iterator currently returning elements. */
    private Iterator<? extends T> iterator;

    /*
     * We track the "meta iterators," the iterators-of-iterators, below.  Usually, topMetaIterator
     * is the only one in use, but if we encounter nested concatenations, we start a deque of

      barrier.await();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  private void checkStackTrace(ExecutionException e) {
    // Our call site for get() should be in the trace.
    int index = findStackFrame(e, getClass().getName(), "getExpectingExecutionException");

    assertThat(index).isNotEqualTo(0);

    // Above our method should be the call to get(). Don't assert on the class

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.Iterator;

/**
 * A mutable object which accumulates double values and tracks some basic statistics over all the
 * values added so far. The values may be added singly or in groups. This class is not thread safe.
 *
 * @author Pete Gillin
 * @author Kevin Bourrillion
 * @since 20.0
 */

   * then the effect of the function is non-existent: we serve storedPermits at exactly the same
   * cost as fresh ones (1/QPS is the cost for each). We use this trick later.
   *
   * If we pick a function that goes /below/ that horizontal line, it means that we reduce the area
   * of the function, thus time. Thus, the RateLimiter becomes /faster/ after a period of

    thread.start();

    boolean done = doneSignal.await(1, TimeUnit.SECONDS);
    if (!done) {
      StringBuilder builder = new StringBuilder();
      for (StackTraceElement trace : thread.getStackTrace()) {
        builder.append("\tat ").append(trace).append('\n');
      }
      fail(builder.toString());
    }
  }

  /**

    thread.start();

    boolean done = doneSignal.await(1, TimeUnit.SECONDS);
    if (!done) {
      StringBuilder builder = new StringBuilder();
      for (StackTraceElement trace : thread.getStackTrace()) {
        builder.append("\tat ").append(trace).append('\n');
      }
      fail(builder.toString());
    }
  }

  /**