code: def __str__(self):
      assert self.location is not None
  
      message = (
          "The following feature file should be included but cannot be found: "
          f"{Exception.__str__(self)}"
      )
      return f"{self.location}: {message}"
  
label_desc: Use image node_id 1 for calling the IncludedFeaNotFound obj's underlying member method code with example usage: obj.__str__() and returns: self, str, message