private void completeExceptionally(boolean closeScanner) {
    resultCache.clear();
    if (closeScanner) {
      closeScanner();
    }
    future.completeExceptionally(new RetriesExhaustedException(tries - 1, exceptions));
  }
This method is used when {@link ScanControllerImpl#suspend} had ever been called to get a
{@link ScanResumerImpl}, but now user stops scan and does not need any more scan results.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncScanSingleRegionRpcRetryingCaller.java