@Override
  public void updateRegionFavoredNodesMapping(String encodedRegionName,
    List<org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.ServerName> favoredNodes) {
  }
Use this method to set what a scanner will reply as we next through
hbase-server/src/test/java/org/apache/hadoop/hbase/master/MockRegionServer.java