public RegionState getRegionState(final RegionInfo regionInfo) {
    RegionStateNode regionStateNode = getRegionStateNode(regionInfo);
    return regionStateNode == null ? null : regionStateNode.toRegionState();
  }
Returns A snapshot of region state nodes for all the regions.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStates.java