old_contents: from flask.ext.sqlalchemy import SQLAlchemy
  
  db = SQLAlchemy()
  
  
  class Message(db.Model):
  
      id = db.Column(db.Integer, primary_key=True)
      recipient = db.Column(db.String, nullable=False)
      data = db.Column(db.String, nullable=False)
  
new_contents: from flask.ext.sqlalchemy import SQLAlchemy
  
  db = SQLAlchemy()
  
subject: remove obsolete model