Why is `event` property required in payload?

[guanzo]

Trying to test my http lambda but seems like I have to send data with an event key? This data format isn't required by AWS afaik.

https://github.com/ashiina/lambda-local/blob/4409022d20b81cb4ff445cf1f8fe3ea7a0736cd2/src/lambdalocal.ts#L94-L96