我无法为Dialog Directive做后端代码，即在启动或进行中以及完成时，dialog_state请帮我构建功能。
参考-
https://medium.com/@jasonrigden/how-to-make-an-alexa-skill-with-python-cb8a6a6c4d85
https://www.youtube.com/watch?v=i9egDifCNu8
https://media.readthedocs.org/pdf/alexa-skills-kit-python-sdk/latest/alexa-skills-kit-python-sdk.pdf
https://developer.amazon.com/docs/custom-skills/dialog-interface-reference.html#delegate