code: public void unlock() throws IOException {
          System.runFinalization();
          if (fileLock != null) {
              try {
                  fileLock.release();
              } catch (ClosedChannelException e) {
                  throw new IOException("Can't close Channel in " + osFile + ".");
              }
              fileLock = null;
          }
      }
docs: tries to unlock the file
  
  @throws IOException