old_contents: import sae
  from tornado.options import options
  options.sqlalchemy_master = 'mysql://%s:%s@%s:%s/%s?charset=utf8' %\
          (sae.const.MYSQL_USER, sae.const.MYSQL_PASS, sae.const.MYSQL_HOST,
           sae.const.MYSQL_PORT, sae.const.MYSQL_DB)
  
  from july import JulyHandler, JulyApplication
  from july.database import db
  
  
  class HomeHandler(JulyHandler):
      def get(self):
          db._ping_db()
          self.write('hello world')
  
  
  handlers = [
      ('/', HomeHandler),
  ]
  
  app = JulyApplication(handlers, wsgi=True)
  
new_contents: import sae
  from tornado.options import options
  from sqlalchemy.pool import NullPool
  options.sqlalchemy_master = 'mysql://%s:%s@%s:%s/%s?charset=utf8' %\
          (sae.const.MYSQL_USER, sae.const.MYSQL_PASS, sae.const.MYSQL_HOST,
           sae.const.MYSQL_PORT, sae.const.MYSQL_DB)
  
  options.sqlalchemy_kwargs = {
      'poolclass': NullPool,
  }
  
  from july import JulyHandler, JulyApplication
  from july.database import db
  
  
  class HomeHandler(JulyHandler):
      def get(self):
          db._ping_db()
          self.write('hello world')
  
  
  handlers = [
      ('/', HomeHandler),
  ]
  
  app = JulyApplication(handlers, wsgi=True, debug=True)
  
subject: fix on sae example