Testing:

```
(ns inventory.core-test
(:require [clojure.test :refer :all]
[inventory.core :as i]))
(def books
[{:title "2001" :author "Clarke" :copies 21}
{:title "Emma" :author "Austen" :copies 10}
{:title "Misery" :author "King" :copies 101}])
(deftest test-finding-books
(is (nil? (i/find-by-title "XY" books))))
(deftest test-finding-books-2
(is (not (nil? (i/find-by-title "Emma" books))))
(is (nil? (i/find-by-title "XY" books))))
```

```
def eval(x, poly):
'''Evaluate at x the polynomial with coefficients given in poly'''
sum = 0
while 1:
sum = sum + poly[0] # Add the next coef.
poly = poly[1:] # Done with that one.
if not poly: break # If no more, done entirely.
sum = sum * x # Mult by x (each coef gets x right numtimes)
return sum
```