removeWaiter(node);
                throw new InterruptedException();
              }

              // Otherwise re-read and check doneness. If we loop then it must have been a spurious
              // wakeup
              localValue = valueField;
              if (localValue != null & notInstanceOfDelegatingToFuture(localValue)) {
                return getDoneValue(localValue);
              }

                removeWaiter(node);
                throw new InterruptedException();
              }

              // Otherwise re-read and check doneness. If we loop then it must have been a spurious
              // wakeup
              localValue = valueField;
              if (localValue != null & notInstanceOfDelegatingToFuture(localValue)) {
                return getDoneValue(localValue);
              }

     *
     * (We promoted a class of warnings into errors because sometimes they indicate real problems.
     * But now we need to "undo" some instance of spurious errors, as discussed in
     * https://github.com/jspecify/checker-framework/issues/8.)
     */
    return removedValue == null ? null : (V) removedValue;
  }

  @Override

   * value is <a href="#bitEquals">bitwise equal</a> to the expected value.
   *
   * <p>May <a
   * href="http://download.oracle.com/javase/7/docs/api/java/util/concurrent/atomic/package-summary.html#Spurious">
   * fail spuriously</a> and does not provide ordering guarantees, so is only rarely an appropriate
   * alternative to {@code compareAndSet}.
   *
   * @param i the index
   * @param expect the expected value

 * but given that any public suffix may become a host without warning, it is better to err on the
 * side of permissiveness and thus avoid spurious rejection of valid sites. Of course, to actually
 * determine addressability of any host, clients of this class will need to perform their own DNS
 * lookups.
 *
 * <p>During construction, names are normalized in two ways:

    RangeMap<Integer, Integer> copy = TreeRangeMap.copyOf(rangeMap);

    assertEquals(rangeMap.asMapOfRanges(), copy.asMapOfRanges());
  }

  // Overriding testEquals because it seems that we get spurious failures when it things empty
  // should be unequal to empty.
  public void testEquals() {
    TreeRangeMap<Integer, Integer> empty = TreeRangeMap.create();

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

  public void testRemoveWaiter_polling() throws Exception {

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

  public void testRemoveWaiter_polling() throws Exception {

          //                ||----w |
          //                ||     ||
          // We need to clear the interrupted bit prior to calling park and maintain it in case we
          // wake up spuriously.
          restoreInterruptedBit = Thread.interrupted() || restoreInterruptedBit;
          LockSupport.park(blocker);
        }
      } else {
        Thread.yield();
      }
      state = get();
    }