'Checks if any tables are present in the current assets database.
Parameters
txn : Transaction
The open transaction to check in.
Returns
has_tables : bool
True if any tables are present, otherwise False.'

def _all_tables_present(self, txn):

    conn = txn.connect()
    for table_name in asset_db_table_names:
        if txn.dialect.has_table(conn, table_name):
            return True
    return False
