docs: def resources_of_config(config):
      """ Returns all resources and models from config.
      """
      return set(             # unique values
          sum([               # join lists to flat list
              list(value)     # if value is iter (ex: list of resources)
              if hasattr(value, '__iter__')
              else [value, ]  # if value is not iter (ex: model or resource)
              for value in config.values()
          ], [])
      )