For given function type `Fn`, and any type `A` (any in this context means we don't restrict the type, and I don't have in mind any type 😉) create a generic type which will take `Fn` as the first argument, `A` as the second, and will produce function type `G` which will be the same as `Fn` but with appended argument `A` as a last one. For example, ```typescript type Fn = (a: number, b: string) => number type Result = AppendArgumentby Maciej Sikora @maciejsikora