Describe an object persisted in DB using interfaces and schema.

in.py

class IDBEventEntry(IDBTable):
    message_id = schema.db.Integer(name='event_id', description='Some docstring here', lenght=12)


class DBObject(TwistarDBObject):

    def getColums():
        """
        Return all db columns.
        """

    dev validateSchama():
        """
        return a deferred with return None if everthing is ok

        raise an DBValidationError if things go wrong.
        """


DBEventEntru(DBObject):
    implements(IDBEventEntry)

    def __init__(self):
        self.message_id = 3