def METHOD_NAME(self, settings, aes):
    settings.set_secret(aes, "GROUP", "KEY", "VERY SECRET")
    # Value not stored as plain text
    assert settings["GROUP"]["KEY"] != "VERY_SECRET"
    # IV stored
    assert settings["GROUP"]["KEY_aes_iv"]
    assert settings.get_secret(aes, "GROUP", "KEY") == "VERY SECRET"