ApplyMiddleware will apply all middleware, the last arguments will be the outer wrap for context passing purposes.

GetID grabs an ID from a context if set otherwise it returns an empty string.

Handler is very basic.

Logger logs requests, this will use an id passed in via SetID().

SetID updates context with the id then increments it.

ID is the only ID we've defined.

ContextID is our type to retrieve our context objects.

Middleware is what all middleware functions will return.