code: def get_assistants(cls, superassistants):
          
          _assistants = cls.load_all_assistants(superassistants)
          result = []
          for supa in superassistants:
              result.extend(_assistants[supa.name])
  
          return result
docs: Returns list of assistants that are subassistants of given superassistants
          (I love this docstring).
  
          Args:
              roles: list of names of roles, defaults to all roles
          Returns:
              list of YamlAssistant instances with specified roles