code: def get_course_certificate(self, course_id, username):
          
          return self.client.certificates(username).courses(course_id).get()
docs: Retrieve the certificate for the given username for the given course_id.
  
          Args:
          * ``course_id`` (str): The string value of the course's unique identifier
          * ``username`` (str): The username ID identifying the user for which to retrieve the certificate
  
          Raises:
  
          HttpNotFoundError if no certificate found for the given user+course.
  
          Returns:
  
          a dict containing:
  
          * ``username``: A string representation of an user's username passed in the request.
          * ``course_id``: A string representation of a Course ID.
          * ``certificate_type``: A string representation of the certificate type.
          * ``created_date`: Datetime the certificate was created (tz-aware).
          * ``status``: A string representation of the certificate status.
          * ``is_passing``: True if the certificate has a passing status, False if not.
          * ``download_url``: A string representation of the certificate url.
          * ``grade``: A string representation of a float for the user's course grade.