@Override
  public void closeScanner(int scannerId) throws TIOError, TIllegalArgument, TException {
    LOG.debug("scannerClose: id=" + scannerId);
    ResultScanner scanner = getScanner(scannerId);
    if (scanner == null) {
      LOG.warn("scanner ID: " + scannerId + "is invalid");
      // While the scanner could be already expired,
      // we should not throw exception here. Just log and return.
      return;
    }
    scanner.close();
    removeScanner(scannerId);
  }
Removes the scanner associated with the specified ID from the internal HashMap.
@param id of the Scanner to remove
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/ThriftHBaseServiceHandler.java