columns.append(Column('muser', String(255), nullable=False, default=''))
columns.append(Column('cluster', Integer, nullable=False, default=0))
self.versions = Table('versions', metadata, *columns)
columns.append(Column('muser', String(255), nullable=False, default=''))
columns.append(Column('cluster', Integer, nullable=False, default=0))
self.versions = Table('versions', metadata, *columns)