AmzObjectLockRetainUntilDate     = "X-Amz-Object-Lock-Retain-Until-Date"
	AmzObjectLockMode                = "X-Amz-Object-Lock-Mode"
	AmzObjectLockLegalHold           = "X-Amz-Object-Lock-Legal-Hold"
)

var (
	// ErrMalformedBucketObjectConfig -indicates that the bucket object lock config is malformed
	ErrMalformedBucketObjectConfig = errors.New("invalid bucket object lock config")

		}
	}

	return &LockedFile{f}, nil
}

// TryLockedOpenFile - tries a new write lock, functionality
// it is similar to LockedOpenFile with with syscall.LOCK_EX
// mode but along with syscall.LOCK_NB such that the function
// doesn't wait forever but instead returns if it cannot
// acquire a write lock.
func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {

	*LockedFile
	mutex sync.Mutex
	refs  int // Holds read lock refs.
}

// IsClosed - Check if the rlocked file is already closed.
func (r *RLockedFile) IsClosed() bool {
	r.mutex.Lock()
	defer r.mutex.Unlock()
	return r.refs == 0
}

// IncLockRef - is used by called to indicate lock refs.
func (r *RLockedFile) IncLockRef() {
	r.mutex.Lock()
	r.refs++
	r.mutex.Unlock()
}

    valueRef.clear();
    assertNotSame(value, map.get(key, loader));
    assertEquals(1, loader.getCount());
    assertEquals(1, segment.count);
  }

  @AndroidIncompatible // Perhaps emulator clock does not update between the two get() calls?
  public void testComputeExpiredEntry() throws ExecutionException {
    CacheBuilder<Object, Object> builder =
        createCacheBuilder().expireAfterWrite(1, TimeUnit.NANOSECONDS);

    valueRef.clear();
    assertNotSame(value, map.get(key, loader));
    assertEquals(1, loader.getCount());
    assertEquals(1, segment.count);
  }

  @AndroidIncompatible // Perhaps emulator clock does not update between the two get() calls?
  public void testComputeExpiredEntry() throws ExecutionException {
    CacheBuilder<Object, Object> builder =
        createCacheBuilder().expireAfterWrite(1, TimeUnit.NANOSECONDS);

}

// RLockHandler - Acquires an RLock.
func (l *lockRESTServer) RLockHandler(args *dsync.LockArgs) (*dsync.LockResp, *grid.RemoteErr) {
	resp := lockRPCRLock.NewResponse()
	success, err := l.ll.RLock(context.Background(), *args)
	if err == nil && !success {
		err = errLockConflict
	}
	return l.makeResp(resp, err)
}

// RUnlockHandler - releases the acquired read lock.

  bool BlockNotStale(const std::shared_ptr<Block>& block)
      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);

  /// Look up a Key in the block cache.
  std::shared_ptr<Block> Lookup(const Key& key) ABSL_LOCKS_EXCLUDED(mu_);

  void MaybeFetch(const Key& key, const std::shared_ptr<Block>& block,
                  TF_Status* status) ABSL_LOCKS_EXCLUDED(mu_);

  /// Trim the block cache to make room for another entry.

		}
	}

	return &LockedFile{File: f}, nil
}

// TryLockedOpenFile - tries a new write lock, functionality
// it is similar to LockedOpenFile with with syscall.LOCK_EX
// mode but along with syscall.LOCK_NB such that the function
// doesn't wait forever but instead returns if it cannot
// acquire a write lock.
func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {

		err = errLockNotInitialized
	default:
		err = errors.New(r.Err)
	}
	return ok, err
}

// RLock calls read lock REST API.
func (c *lockRESTClient) RLock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
	return c.call(ctx, lockRPCRLock, &args)
}

// Lock calls lock REST API.
func (c *lockRESTClient) Lock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
	return c.call(ctx, lockRPCLock, &args)
}

func (r *ReplicationStats) updateMovingAvg() {
	r.RLock()
	for _, s := range r.Cache {
		for _, st := range s.Stats {
			st.XferRateLrg.measure.updateExponentialMovingAverage(time.Now())
			st.XferRateSml.measure.updateExponentialMovingAverage(time.Now())
		}
	}
	r.RUnlock()
}

// ActiveWorkers returns worker stats
func (r *ReplicationStats) ActiveWorkers() ActiveWorkerStat {
	r.wlock.RLock()
	defer r.wlock.RUnlock()