def METHOD_NAME(cls):
    cls.test_db_name = f"{POSTGRES_DB}_testdb".lower()
    # Connect with database
    # NOTE: Not using context manager because it will start a transaction.
    # https://stackoverflow.com/a/68112827/3436502
    con = psycopg2.connect(
        database=POSTGRES_DB,
        host=POSTGRES_HOST,
        password=POSTGRES_PASSWORD,
        port=POSTGRES_PORT,
        user=POSTGRES_USER,
    )
    # Create a new db. Drop if already exists.
    # TODO: Don't drop here, just clear the data.
    #   and DROP after all TestClass are done.
    con.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT)
    with con.cursor() as cursor:
        cursor.execute(f"DROP DATABASE IF EXISTS {cls.test_db_name};")
        cursor.execute(f"CREATE DATABASE {cls.test_db_name};")
    con.commit()
    con.close()
    # Connect to newly created DB
    cls.db_con = psycopg2.connect(
        database=cls.test_db_name,
        host=POSTGRES_HOST,
        password=POSTGRES_PASSWORD,
        port=POSTGRES_PORT,
        user=POSTGRES_USER,
    )
    # Setup newly created DB
    with open(os.path.join(BASE_DIR, "set_up_db.sql")) as fp:
        cls.__db_query(fp.read())
    # XXX: Force overwrite main postgres DB helper methods.
    #   (To use newly creatd test db)
    cls.original_auth_db_connection = auth.postgresDB._db_connection
    cls.original_auth__del__ = auth.postgresDB.__del__
    auth.postgresDB._db_connection = cls.db_con
    auth.postgresDB.__del__ = cls.no_op
    cls.db = auth.postgresDB()