anchor.diff:  
     (setf (gethash 8 table-of-cube-roots) 2)
     (setf (gethash -3 table-of-cube-roots) -27)
  -  (assert-equal ___ (gethash -3 table-of-cube-roots))
  -  (assert-equal ___ (hash-table-count table-of-cube-roots))
  +  (assert-equal -27 (gethash -3 table-of-cube-roots))
  +  (assert-equal 3 (hash-table-count table-of-cube-roots))
   
     "accessing unset keys returns nil"
  -  (assert-equal ___ (gethash 125 table-of-cube-roots))))
  +  (assert-equal nil (gethash 125 table-of-cube-roots))))
   
   
   (define-test test-hash-key-equality
  
positive.code:       (setf value-and-exists (multiple-value-list (gethash "Obama" prev-pres)))
        (assert-equal value-and-exists '("Bush" t))
        (setf value-and-exists (multiple-value-list (gethash "Lincoln" prev-pres)))
        (assert-equal value-and-exists ____)
        (setf value-and-exists (multiple-value-list (gethash "Washington" prev-pres)))
        (assert-equal value-and-exists ____)
        (setf value-and-exists (multiple-value-list (gethash "Franklin" prev-pres)))
        (assert-equal value-and-exists ____)))
  
  
  (define-test test-make-your-own-hash-table
      "make a hash table that meets the following conditions"
    (let ((colors (make-hash-table))
          (values (make-hash-table)))
  
      (assert-equal (hash-table-count colors) 4)
      (setf values (list (gethash "blue" colors)
                         (gethash "green" colors)
                         (gethash "red" colors)))
      (assert-equal values '((0 0 1) (0 1 0) (1 0 0)))))
  
negative.code:     (setf (gethash "one" hash-table-default) "uno")
  
      "count how many unique key-value pairs in each"
      (assert-equal 2 (hash-table-count hash-table-eq))
      (assert-equal 1 (hash-table-count hash-table-equal))
      (assert-equal 2 (hash-table-count hash-table-default))))
  
  
  (define-test test-hash-table-equality
  