The input (included in fixed tests) includes double spaces between each set of symbols (I don't know how to display it correctly in markdown), and the correct output is "9 8 7 6 5 4 3 2 1 0" in this case.

When there is a flaw you get for example:

Test Failed
	`actual` not equal to `expected`.
	2/3 mismatches (average diff: 144)
	[1]  0 -   1 ==   -1
	[2] 32 - 320 == -288

Here a 0 and 32 are returned instead of (a fake) 1 and 320.