anchor.diff:                      new-value (find-entity-by-uid new-value)))
               (t
                (add-modifier entity "entity" "uid" new-value
  -                           :description "Unique human-usable identifier for entity."))))))
  +                           :description "Unique external identifier for entity."))))))
   
   (defun find-entity-by-uid (uid)
     (with-db ()
  
positive.code:                         :name "entity-system-processing")))
  
  (defun teardown-entity-system ()
    (when (and *es-thread* (bt:thread-alive-p *es-thread*))
      (bt:destroy-thread *es-thread*))
    (setf *es-thread* nil))
  
  (defdao entity ()
    ((id :col-type serial :reader id)
  
negative.code:     (maphash-values #'funcall callbacks)))
  
  (defparameter *ticks-per-second* 5)
  (defvar *entity-system-thread* nil)
  (defun init-entity-system ()
    (setf *entity-system-thread*
          (bt:make-thread (lambda ()
                            (loop with timer = (make-timer *ticks-per-second*)
                               do (timer-tick timer)
  