anchor.diff:        (htree:add-child web-page2 history)
         (prove:is (hash-table-count (htree:entries history))
                   1)
  -      (prove:is (title (htree:value (first-hash-table-key (htree:entries history))))
  +      (prove:is (title (htree:value (htree::first-hash-table-key (htree:entries history))))
                   "Same page, another title"))
       (let ((history (htree:make)))
         (htree:add-child web-page1 history)
  
positive.code:    (title ""))
    (:accessor-name-transformer #'class*:name-identity))
  
  (defun first-hash-table-key (hash-table)
    (with-hash-table-iterator (next-entry hash-table)
      (nth-value 1 (next-entry))))
  
  (prove:subtest "Compound entry uniqueness"
    (let ((web-page1 (make-instance 'web-page :url "http://example.org"
                                              :title "Example page"))
  
negative.code:         (url2 "https://nyxt.atlas.engineer"))
      (htree:add-child url1 history)
      (htree:set-current-owner history "b")
      (htree:add-child url2 history :creator-identifier "a")
      (prove:is (length (htree:nodes (htree:owner history "a")))
                1)
      (prove:is (length (htree:nodes (htree:owner history "b")))
  