private TableDescriptor getDescriptor(TableName tableName) throws IOException {
    ClusterInfoProvider service = this.provider;
    if (service == null) {
      return null;
    }
    return service.getTableDescriptor(tableName);
  }
return TableDescriptor for a given tableName
@param tableName the table name
hbase-balancer/src/main/java/org/apache/hadoop/hbase/master/balancer/RegionHDFSBlockLocationFinder.java