new_contents: from sqlalchemy import *
  from migrate import *
  from raggregate.guid_recipe import GUID
  
  
  def upgrade(migrate_engine):
      meta = MetaData(bind=migrate_engine)
      users = Table('users', meta, autoload=True)
      notify_by_mailc = Column('notify_by_mail', Boolean, default=True)
      notify_by_mailc.create(users)
  
  
  def downgrade(migrate_engine):
      meta = MetaData(bind=migrate_engine)
      users = Table('users', meta, autoload=True)
      users.c.notify_by_mail.drop()
  
subject: Include migration for notify_by_mail. ...