+ (assert (string= (documentation #'docfoo t) "bar"))
+ (assert (string= (setf (documentation #'docfoo t) "zot") "zot"))
+ (assert (string= (documentation #'docfoo t) "zot"))
+ (assert (string= (documentation 'docfoo 'function) "baz"))
+ (assert (not (setf (documentation 'docfoo 'function) nil)))
+ (assert (string= (documentation 'docfoo 'function) "zot")))