public TransitRegionStateProcedure[] createRoundRobinAssignProcedures(List<RegionInfo> hris) {
    return createRoundRobinAssignProcedures(hris, null);
  }
Create round-robin assigns. Use on table creation to distribute out regions across cluster.
@return AssignProcedures made out of the passed in <code>hris</code> and a call to the balancer
        to populate the assigns with targets chosen using round-robin (default balancer
        scheme). If at assign-time, the target chosen is no longer up, thats fine, the
        AssignProcedure will ask the balancer for a new target, and so on.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java