anchor.diff:  Postgres type *ID-TYPE*) in MODEL, a symbol, and return a parse of the
   JSON string by the the function of one argument designated by
   FROM-JSON.  Make it #'identity to return just the JSON string proper."
  +  (ensure-model-query model 'get$)
     (funcall from-json (with-transaction-type (read-committed-ro)
                          (get$ model id))))
   
  
positive.code: JSON strings.  Returns ID on success, NIL if there was no such ID
  found."
    (log:debug "Attempt update of ~A" id)
    (with-retry-serialization-failure ("update")
      (with-transaction-type (repeatable-read-rw)
        (insert-old$ model id)
  
negative.code: value of the id to be used for the DB insert and OBJECT.  TO-JSON must
  be a function designator for a function of one argument to serialize
  lisp objects to JSON strings.  Return the id."
    (unless use-id
      (ensure-model-query model 'nextval-sequence$))
    (ensure-model-query model 'insert$)
    (with-transaction-type (read-committed-rw)
      (let* ((id (if use-id use-id (nextval-sequence$ model)))
             (object (if stash-id
  