   "Return a sorted list of the keys in the given hash table H."
   (mapcar 'intern (sort (mapcar 'symbol-name (ht-keys h)) 'string<)))
 
-(defun configuration-layer/load-file (file)
-  "Assure that FILE is loaded only once."
-  (unless (member file configuration-layer--loaded-files)
-    (load file)
-    (push file configuration-layer--loaded-files)))
-
 (defun configuration-layer/get-excluded-packages (layers)
   "Read `layer-excluded-packages' lists for all passed LAYERS and return a list
 of all excluded packages."


(defvar configuration-layer-excluded-packages '()
  "List of all excluded packages declared at the layer level.")

(defvar configuration-layer--loaded-files '()
  "List of loaded files.")

(defun configuration-layer/sync ()
  "Synchronize declared layers in dotfile with spacemacs."

             (dir (plist-get (cdr layer) :dir))
             (pkg-file (concat dir "packages.el")))
        (when (file-exists-p pkg-file)
          (load pkg-file)
          (let ((excl-var (intern (format "%s-excluded-packages"
                                          (symbol-name layer-sym)))))
            (when (boundp excl-var)
