def create_from(cls, engine, session, priority=DEFAULT_SQL_PRIORITY):
        """Instantiate a SqlObserver with an existing engine and session."""
        self = cls.__new__(cls)  # skip __init__ call
        self.engine = engine
        self.session = session
        self.priority = priority
        self.run = None
        self.lock = Lock()
        return self
Instantiate a SqlObserver with an existing engine and session.
sacred/observers/sql.py