private Scan setDefaultScanConfig(Scan scan) {
    // always create a new scan object as we may reset the start row later.
    Scan newScan = ReflectionUtils.newInstance(scan.getClass(), scan);
    if (newScan.getCaching() <= 0) {
      newScan.setCaching(defaultScannerCaching);
    }
    if (newScan.getMaxResultSize() <= 0) {
      newScan.setMaxResultSize(defaultScannerMaxResultSize);
    }
    return newScan;
  }
The implementation of RawAsyncTable.
<p/>
The word 'Raw' means that this is a low level class. The returned {@link CompletableFuture} will
be finished inside the rpc framework thread, which means that the callbacks registered to the
{@link CompletableFuture} will also be executed inside the rpc framework thread. So users who use
this class should not try to do time consuming tasks in the callbacks.
@since 2.0.0
@see AsyncTableImpl
hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTableImpl.java