So you define your filter function by saying it can use anything that has the next and the len functions. Cool. If a type A defined in module_a doesn’t have th

So you define your filter function by saying it can use anything that has the next and the len functions. Cool. If a type A defined in module_a doesn’t have the functions defined in its module, should it still be filterable? If the required function is defined in a module_b should A be filterable?