anchor.diff:                                :source-msg msg
                                 ;; @TODO: right now returns a list, make it return t or nil
                                 :raise-event-on-true
  -      (if (= is_custom TRUE)
  +      (if (= is_custom (get-constant-value 'event_bullet_world-msg:AddPhysicsEvent :TRUE))
           #'(lambda (event)
             (with-fields (custom_function) (source-msg event)
               ;; USE: https://github.com/mabragor/cl-secure-read ???
  
positive.code:   "Callback for adding new events and starting a thread for them "
    (ros-info EVENT_BULLET_WORLD "Adding Physics Event to list")
    (with-fields (event_name constraint_list ros_binding_type is_custom constraint_relation
                  custom_function TRUE FALSE) msg
      (add-physics-event (make-instance 'physics-event
                                :event-name event_name
                                :response-type ros_binding_type
  
negative.code: 
  ; (defparameter *add-event-msg* (make-fluent :name :new-event) "New event to be checked for")
  ; (defparameter *raise-event-msg* (make-fluent :name :new-event) "New event raised")
  (defun get-constant-value (msg slot)
    (roslisp-msg-protocol:symbol-code msg slot))
  
  (defparameter *raise-event-pub* nil "Raised event published by this publisher")
  ; (defparameter *add-event-sub* nil "New events to be added read from here")
  