const memo = memoize(fn);
memo(42); // miss — computed and cached
memo(99); // miss — computed and cached
memo(42); // hit — returned from cacheA cache miss means the input is new; the function runs and stores the result.
When an argument is not in the cache, the function must compute the result.
Challenge: Verify that calling a memoized function with new arguments computes results for cache misses.