code: public TwoPhaseMove prepareMove(Path src, Path dst) throws FileAlreadyExistsException {
  		return new TwoPhaseMove(src, dst);
  	}
docs: Prepares to update any open file references during a move operation.
  MUST be invoked using a try-with-resource statement and committed after the physical file move succeeded.
  
  @param src The ciphertext file path before the move
  @param dst The ciphertext file path after the move
  @return Utility to update OpenCryptoFile references.
  @throws FileAlreadyExistsException Thrown if the destination file is an existing file that is currently opened.