def METHOD_NAME(self):
    """A slot cannot be both a key and an identifier"""
    fn = env.input_path("loadererror8.yaml")
    with self.assertRaises(ValueError, msg="A slot cannot be both a key and identifier") as e:
        _ = SchemaLoader(fn).resolve()
    self.assertIn(
        "A slot cannot be both a key and identifier at the same time",
        str(e.exception),
    )
    fn = env.input_path("loadererror9.yaml")
    with self.assertRaises(ValueError, msg="A slot cannot be both a key and identifier") as e:
        _ = SchemaLoader(fn).resolve()
    self.assertIn(
        "A slot cannot be both a key and identifier at the same time",
        str(e.exception),
    )