private Table ensureGetTable(String catName, String dbName, String tblName)
      throws NoSuchObjectException, MetaException {
    return convertToTable(ensureGetMTable(catName, dbName, tblName));
  }
Gets the table object for a given table, throws if anything goes wrong.
@param dbName Database name.
@param tblName Table name.
@return Table object.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java