If you can explain what it is supposed to do, I don't care a whit if you make up a method that probably exists in a standard library somewhere (Guava / Apache C

If you can explain what it is supposed to do, I don't care a whit if you make up a method that probably exists in a standard library somewhere (Guava / Apache Commons, or wherever). If it's slightly more obscure, you might have to write pseudocode to show you know how it might be implemented.