Cannot overwrite `Note` model once compiled.

I just copy your code but configure with my local mongoDB to test such APIs, those RESTful API are only feasible once when I run "sls offline" to deploy them natively, then when I use postman to call the same method for twice, it failed and here is the Error:
'OverwriteModelError: Cannot overwrite `Note` model once compiled.'
Could you help me out? Thanks!!