(defmacro build-instance (module config &optional (gensym-name "G"))
  (let* ((gensym (gensym gensym-name))
         (package (make-package gensym :use '(#:cl)))
         (query-handler (intern (symbol-name 'query-handler) package))
         (this (intern (symbol-name 'this) package)))
    `(progn
       (defpackage ,gensym
         (:use :cl)
         (:export ',query-handler ',this))
       (defparameter ,query-handler ,module)
       (defparameter ,this ,module)
       ,package)))