code: protected void doCloseCommunicationLink() {
          if (null != this.fileSystem && !this.fileSystem.isClosed()) {
              try {
                  this.fileSystem.close();
              }
              catch (IOException ex) {
                  VfsLog.warn(getLogger(), log,
                          "vfs.provider.iso/close-iso-file.error :" + this.fileSystem, ex);
              }
          }
      }
docs: Closes the underlying .iso file.