code: def get_all_completed_tasks(self, api_token, **kwargs):
          
          params = {
              'token': api_token
          }
          return self._get('get_all_completed_items', params, **kwargs)
docs: Return a list of a user's completed tasks.
  
          .. warning:: Requires Todoist premium.
  
          :param api_token: The user's login api_token.
          :type api_token: str
          :param project_id: Filter the tasks by project.
          :type project_id: str
          :param limit: The maximum number of tasks to return
              (default ``30``, max ``50``).
          :type limit: int
          :param offset: Used for pagination if there are more tasks than limit.
          :type offset: int
          :param from_date: Return tasks with a completion date on or older than
              from_date. Formatted as ``2007-4-29T10:13``.
          :type from_date: str
          :param to: Return tasks with a completion date on or less than
              to_date. Formatted as ``2007-4-29T10:13``.
          :type from_date: str
          :return: The HTTP response to the request.
          :rtype: :class:`requests.Response`
  
          >>> from pytodoist.api import TodoistAPI
          >>> api = TodoistAPI()
          >>> response = api.login('john.doe@gmail.com', 'password')
          >>> user_info = response.json()
          >>> user_api_token = user_info['api_token']
          >>> response = api.get_all_completed_tasks(user_api_token)
          >>> completed_tasks = response.json()