docs: private void closeFileChannel() {
          try {
              if (this.databaseIndexCache != null) {
                  this.databaseIndexCache.destroy();
              }
              if (this.inputChannel != null) {
                  this.inputChannel.close();
              }
          } catch (Exception e) {
              LOGGER.log(Level.SEVERE, e.getMessage(), e);
          }
      }