old_contents: import model.wu.user
  from model.wu.user import User
  
  
  def init_context(app):
      model.wu.user.init_context(app)
  
  # todo evaluate a parameter and decide which package to use (wu, hss, test(?))
  
new_contents: import os
  
  model_name = os.getenv('SIPA_MODEL', 'sample')
  
  module = __import__('{}.{}.user'.format(__name__, model_name),
                      fromlist='{}.{}'.format(__name__, model_name))
  
  init_context = module.init_context
  User = module.User
  query_gauge_data = module.query_gauge_data
  
subject: Load model dynamically via envvar 'SIPA_MODEL'