public String getCat() {
    return cat;
  }
Build a TableName from a string of the form [[catalog.]database.]table.
@param name name in string form, not null
@param defaultCatalog default catalog to use if catalog is not in the name.  If you do not
                      know it you can get it from SessionState.getCurrentCatalog() if you
                      want to use the catalog from the current session, or from
                      MetaStoreUtils.getDefaultCatalog() if you do not have a session or
                      want to use the default catalog for the Hive instance.
@param defaultDatabase default database to use if database is not in the name.  If you do
                       not now it you can get it from SessionState.getCurrentDatabase() or
                       use Warehouse.DEFAULT_DATABASE_NAME.
@param tableMetaRef When querying Iceberg meta ref, e.g. metadata table or branch, set this parameter.
@return TableName
@throws IllegalArgumentException if a non-null name is given
storage-api/src/java/org/apache/hadoop/hive/common/TableName.java