public List<HRegionLocation> getRegionsOfTableForReopen(TableName tableName) {
    return getTableRegionStateNodes(tableName).stream().map(this::createRegionForReopen)
      .filter(r -> r != null).collect(Collectors.toList());
  }
Get the regions to be reopened when modifying a table.
<p/>
Notice that the {@code openSeqNum} in the returned HRegionLocation is also used to indicate the
state of this region, positive means the region is in {@link State#OPEN}, -1 means
{@link State#OPENING}. And for regions in other states we do not need reopen them.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStates.java