return statsCounterSupplier;
  }

  /**
   * Builds a cache, which either returns an already-loaded value for a given key or atomically
   * computes or retrieves it using the supplied {@code CacheLoader}. If another thread is currently
   * loading the value for this key, simply waits for that thread to finish and returns its loaded

      return "Suppliers.compose(" + function + ", " + supplier + ")";
    }

    private static final long serialVersionUID = 0;
  }

  /**
   * Returns a supplier which caches the instance retrieved during the first call to {@code get()}
   * and returns that value on subsequent calls to {@code get()}. See: <a
   * href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
   *

    }
  }

  static void verifyThreadWasNotInterrupted() {
    assertFalse(Thread.currentThread().isInterrupted());
  }

  static void clearInterrupt() {
    Thread.interrupted();
  }

  /**
   * Retrieves the result of a {@code Future} known to be done but uses the {@code get(long,
   * TimeUnit)} overload in order to test that method.
   */
  static <V> V getDoneFromTimeoutOverload(Future<V> future) throws ExecutionException {

 * such as {@link java.io.Reader#read()}, do not expose this information; the only way to discover
 * whether there is any data left is by trying to retrieve it. These types of data sources are
 * ordinarily difficult to write iterators for. But using this class, one must implement only the
 * {@link #computeNext} method, and invoke the {@link #endOfData} method when appropriate.
 *