* backing set. The returned map does not support put operations.
   *
   * <p><b>Warning:</b> If the function rejects {@code null}, caution is required to make sure the
   * set does not contain {@code null}, because the view cannot stop {@code null} from being added
   * to the set.
   *
   * <p><b>Warning:</b> This method assumes that for any instance {@code k} of key type {@code K},

    while ((notification = removalNotificationQueue.poll()) != null) {
      try {
        removalListener.onRemoval(notification);
      } catch (Throwable e) {
        logger.log(Level.WARNING, "Exception thrown by removal listener", e);
      }
    }
  }

  @SuppressWarnings("unchecked")
  final Segment<K, V>[] newSegmentArray(int ssize) {

              restoreInterruptIfIsInterruptedException(e);
              logger.get().log(WARNING, "thrown by close()", e);
            }
          });
    } catch (RejectedExecutionException e) {
      if (logger.get().isLoggable(WARNING)) {
        logger
            .get()
            .log(
                WARNING,
                String.format("while submitting close to %s; will close inline", executor),

    while ((notification = removalNotificationQueue.poll()) != null) {
      try {
        removalListener.onRemoval(notification);
      } catch (Throwable e) {
        logger.log(Level.WARNING, "Exception thrown by removal listener", e);
      }
    }
  }

  @SuppressWarnings("unchecked")
  final Segment<K, V>[] newSegmentArray(int ssize) {