<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def init(cls, conn_string=None):
 """Return the unique Meta class."""

        if conn_string:
            _update_meta(conn_string)
            # We initialize the engine within the models module because models'
            # schema can depend on which data types are supported by the engine
            Meta.Session = new_sessionmaker()
            Meta.engine = Meta.Session.kw["bind"]
            logger.info(
                f"Connecting user:{Meta.DBUSER} "
                f"to {Meta.DBHOST}:{Meta.DBPORT}/{Meta.DBNAME}"
            )
            Meta._init_db()

        if not Meta.log_path:
            init_logging()

        return cls