code: def update_stack(self, fqn, template, old_parameters, parameters, tags,
                       force_interactive=False, force_change_set=False,
                       stack_policy=None, **kwargs):
          
          logger.debug("Attempting to update stack %s:", fqn)
          logger.debug("    parameters: %s", parameters)
          logger.debug("    tags: %s", tags)
          if template.url:
              logger.debug("    template_url: %s", template.url)
          else:
              logger.debug("    no template url, uploading template directly.")
          update_method = self.select_update_method(force_interactive,
                                                    force_change_set)
  
          return update_method(fqn, template, old_parameters, parameters,
                               stack_policy=stack_policy, tags=tags, **kwargs)
docs: Update a Cloudformation stack.
  
          Args:
              fqn (str): The fully qualified name of the Cloudformation stack.
              template (:class:`stacker.providers.base.Template`): A Template
                  object to use when updating the stack.
              old_parameters (list): A list of dictionaries that defines the
                  parameter list on the existing Cloudformation stack.
              parameters (list): A list of dictionaries that defines the
                  parameter list to be applied to the Cloudformation stack.
              tags (list): A list of dictionaries that defines the tags
                  that should be applied to the Cloudformation stack.
              force_interactive (bool): A flag that indicates whether the update
                  should be interactive. If set to True, interactive mode will
                  be used no matter if the provider is in interactive mode or
                  not. False will follow the behavior of the provider.
              force_change_set (bool): A flag that indicates whether the update
                  must be executed with a change set.
              stack_policy (:class:`stacker.providers.base.Template`): A template
                  object representing a stack policy.