public List<RegionStateNode> getRegionsInTransition() {
    return regionStates.getRegionsInTransition();
  }
Used by the client (via master) to identify if all regions have the schema updates
@return Pair indicating the status of the alter command (pending/total)
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java