code: def launch(self, f):
          
          self._launch_view_func = f
  
          @wraps(f)
          def wrapper(*args, **kw):
              self._flask_view_func(*args, **kw)
          return f
docs: Decorator maps a view function as the endpoint for an Alexa LaunchRequest and starts the skill.
  
          @ask.launch
          def launched():
              return question('Welcome to Foo')
  
          The wrapped function is registered as the launch view function and renders the response
          for requests to the Launch URL.
          A request to the launch URL is verified with the Alexa server before the payload is
          passed to the view function.
  
          Arguments:
              f {function} -- Launch view function