code: func TryExclusiveKeyLock(lockDir string, key string) (*KeyLock, error) {
  	return createAndLock(lockDir, key, keyLockExclusive|keyLockNonBlocking)
  }
docs: // TryExclusiveLock takes an exclusive lock on the key without blocking.
  // lockDir is the directory where the lock file will be created.
  // It will return ErrLocked if any lock is already held.