Besen `Array.prototype.slice` bug

besenSliceCall.js

var slice = Array.prototype.slice,
    arrayLike = {0: 'a', 1: 'b', 2: 'c', 3: 'd', length:4},
    a = slice.call(arrayLike), // undefined
    b = slice.call(arrayLike, undefined); // the array as expected
 
print(a); // undefined
print(b); // "a,b,c,d"