public void preScannerOpen(final Scan scan) throws IOException {
    execOperation(coprocEnvironments.isEmpty() ? null : new RegionObserverOperationWithoutResult() {
      @Override
      public void call(RegionObserver observer) throws IOException {
        observer.preScannerOpen(this, scan);
      }
    });
  }
@param scan the Scan specification
@exception IOException Exception
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RegionCoprocessorHost.java