I just tried putting that in tonight, but got this error:
```racket
; Type Checker: Type (-> Any Boolean : #:+ Port) could not
;   be converted to a contract: cannot generate contract for function type with
;   filters or objects.
;   in: (-> Any Boolean : #:+ Port)
```
So, I've left that part of the type spec for ```ssl-port?``` commented out in the subsequent commit.