code: def add_user_role(self, user, role):
          
          self.project_service.set_auth(self._token_project)
          self.project_service.add_user_role(user, role)
docs: Add role to given user.
  
          Args:
              user (string): User name.
              role (string): Role to assign.
  
          Raises:
              requests.HTTPError on failure.