code: def __init__(self, file, name):
      self.file = file.relpath
      self.name = name
      super().__init__(
          f"Stage '{self.name}' not found inside '{self.file}' file"
      )
  
imports: from dvc.exceptions import DvcException
label_desc: Use image node_id 1 to create a new StageNotFound object from inherited base classes: DvcException, KeyError with example: obj = StageNotFound(file, name)