(let ((db (make-hash-table :test #'equal)))
  (defun get-db (key) (gethash key db))
  (defun put-db (key val) (setf (gethash key db) val))
  (defun return-db () db)
  (defun peek-db ()
    (loop for k being the hash-keys in db using (hash-value v)
       do (print k)))
  (defun clear-db () (clrhash db)))