private Pair<ServerName, RegionStateNode>
    randomlySetOneRegionStateToSplitting(RSGroupInfo newGroup) throws IOException {
    // get target server to move, which should has more than one regions
    // randomly set a region state to SPLITTING to make move fail
    return randomlySetRegionState(newGroup, RegionState.State.SPLITTING, tableName);
  }
Randomly choose a region to set state.
@param newGroup target group
@return source server of region, and region state
@throws IOException if methods called throw
hbase-server/src/test/java/org/apache/hadoop/hbase/rsgroup/TestRSGroupsAdmin2.java