code: public static synchronized File createSwapFile() throws IOException {
  		File swapFile = createSwapFile(SWAP_FILE_PREFIX, SWAP_FILE_SUFFIX);
  		// works reliably only on Unix platforms!
  		swapFile.deleteOnExit();
  		return swapFile;
  	}
docs: Creates a new, empty swap file, ready for use. It is guaranteed
  that this swap file will be removed from the system either on
  JVM shutdown (Unix platforms) or on subsequent use of this class
  (Win32 platforms).
  @return A new swap file.
  @throws IOException