old_contents: from datetime import datetime
  
  from sqlalchemy import *
  from migrate import *
  
  meta = MetaData()
  
  
  def upgrade(migrate_engine):
      meta.bind = migrate_engine
      dataset = Table('dataset', meta, autoload=True)
      account = Table('account', meta, autoload=True)
  
      source_table = Table('source', meta,
          db.Column('id', db.Integer, primary_key=True),
          db.Column('url', db.Unicode),
          db.Column('analysis', JSONType, default=dict),
          db.Column('created_at', db.DateTime, default=datetime.utcnow),
          db.Column('dataset_id', db.Integer, db.ForeignKey('dataset.id')),
          db.Column('creator_id', db.Integer, db.ForeignKey('account.id'))
          )
  
      source_table.create()
  
  def downgrade(migrate_engine):
      raise NotImplementedError()
  
  
  
  
new_contents: from datetime import datetime
  
  from sqlalchemy import *
  from migrate import *
  
  meta = MetaData()
  
  
  def upgrade(migrate_engine):
      meta.bind = migrate_engine
      dataset = Table('dataset', meta, autoload=True)
      account = Table('account', meta, autoload=True)
  
      source_table = Table('source', meta,
          Column('id', Integer, primary_key=True),
          Column('url', Unicode),
          Column('analysis', Unicode, default=dict),
          Column('created_at', DateTime, default=datetime.utcnow),
          Column('dataset_id', Integer, ForeignKey('dataset.id')),
          Column('creator_id', Integer, ForeignKey('account.id'))
          )
  
      source_table.create()
  
  def downgrade(migrate_engine):
      raise NotImplementedError()
  
  
  
  
subject: fix migration to not depend on model.meta.