* ParametricNullness parametric nullness}. Sometimes, code may receive a null {@code T} but store
   * a "null sentinel" to take its place. When the time comes to convert it back to a {@code T} to
   * return to a caller, the code needs to a way to return {@code null} from a method that returns
   * "plain {@code T}." This API provides that.
   */
  @SuppressWarnings({"nullness", "TypeParameterUnusedInFormals", "ReturnMissingNullable"})

      if (isSatisfied(guard)) {
        guard.condition.signal();
        break;
      }
    }
  }

  /**
   * Exactly like signalNextWaiter, but caller guarantees that guardToSkip need not be considered,
   * because caller has previously checked that guardToSkip.isSatisfied() returned false. An
   * optimization for the case that guardToSkip.isSatisfied() may be expensive.
   *

   * of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the
   * calling thread. Tasks are run to completion before a {@code Future} is returned to the caller
   * (unless the executor has been shutdown).
   *
   * <p>The returned executor is backed by the executor returned by {@link
   * MoreExecutors#newDirectExecutorService} and subject to the same constraints.
   *

   * themselves their proper values under GWT, since GWT's EnumMap does need the Class instance.
   *
   * Note that sometimes these fields *do* have correct values under J2CL: They will if the caller
   * calls `create(Foo.class)`, rather than `create(map)`. That's fine; we just shouldn't rely on
   * it.
   */
  transient Class<K> keyTypeOrObjectUnderJ2cl;
  transient Class<V> valueTypeOrObjectUnderJ2cl;

  /**

            throw ioe;
    }
    public void run() {
        Thread run_thread = Thread.currentThread();
        Exception ex0 = null;

        try {
            /* We cannot synchronize (run_thread) here or the caller's
             * thread.wait( timeout ) cannot reaquire the lock and
             * return which would render the timeout effectively useless.
             */
            doConnect();
        } catch( Exception ex ) {

        return disconnect(hard, true);
    }


    /**
     * Disconnect the transport
     * 
     * @param hard
     * @param inUse
     *            whether the caller is holding a usage reference on the transport
     * @return whether conenction was in use
     * @throws IOException
     */
    public synchronized boolean disconnect ( boolean hard, boolean inUse ) throws IOException {

    }

    throw new IllegalArgumentException(
        Platform.format("key %s not found in entries %s", newEntry.getKey(), expected));
  }

  /**
   * Wrapper for {@link Map#get(Object)} that forces the caller to pass in a key of the same type as
   * the map. Besides being slightly shorter than code that uses {@link #getMap()}, it also ensures
   * that callers don't pass an {@link Entry} by mistake.
   */

        }
      }

      @Override
      public Entry<E> next() {
        if (!hasNext()) {
          throw new NoSuchElementException();
        }
        // requireNonNull is safe because current is only nulled out after iteration is complete.
        Entry<E> result = wrapEntry(requireNonNull(current));
        prevEntry = result;
        if (current.succ() == header) {
          current = null;
        } else {

        // ignore
      }
    }
  }

  /**
   * Cleans up the given reference and any other references already in the queue. Catches and logs
   * all throwables.
   *
   * @return true if the caller should continue to wait for more references to be added to the
   *     queue, false if the associated FinalizableReferenceQueue is no longer referenced.
   */
  private boolean cleanUp(Reference<?> firstReference) {

   * href="https://goo.gl/MplK6I">URL form parameter names and values</a>. Escaping is performed
   * with the UTF-8 character encoding. The caller is responsible for <a
   * href="https://goo.gl/9EfkM1">replacing any unpaired carriage return or line feed characters
   * with a CR+LF pair</a> on any non-file inputs before escaping them with this escaper.
   *