old_contents: 
  from jinja2 import Environment, FileSystemLoader, TemplateNotFound
  
  def create_template_environment(searchpaths=[], globals={}, filters={}, tests={}):
      env = Environment(
          loader=FileSystemLoader(searchpaths),
          extensions=['jinja2.ext.i18n']
      )
      env.globals.update(globals)
      env.filters.update(filters)
      env.tests.update(tests)
      return env
  
new_contents: 
  from jinja2 import Environment, FileSystemLoader, TemplateNotFound
  
  def create_template_environment(searchpaths=[], globals={}, filters={}, tests={}):
      env = Environment(
          loader=FileSystemLoader(searchpaths),
          extensions=['jinja2.ext.i18n', 'jinja2.ext.do',
                      'jinja2.ext.loopcontrols']
      )
      env.globals.update(globals)
      env.filters.update(filters)
      env.tests.update(tests)
      return env
  
subject: use more template extensions