And it doesn't really matter -- I don't want you understand why it doesn't have the if statement, but I want you to understand that sometimes you can see a problem in a different way and rewrite it so that a special case goes away and becomes the normal case.
Põhimõtteliselt siin vahet pole. Polegi oluline aru saada, miks siin 'if' lausendit pole, aga ma tahan, et saaksite aru, et teinekord on probleemi võimalik vaadata teise nurga alt ja kirjutada see ümber nii,  et erisus kaob ära ja sellest saab tavaline kood.