(let [{: head } (require :lib.head)]
  (let [given "a lift of elements"
        it "returns the first element of a list"
        expected :apple
        actual (head [:apple :orange :pear])]
    (assert (= actual expected) (.. "Given " given " it " it)))
  (let [given "an empty list"
        it "returns an empty list"
        expected 0
        actual (length (head []))]
    (assert (= actual expected) (.. "Given " given " it " it))))