Define the _make method, which takes one iterable argument (and no self argument: the purpose of _make is to make a new object; see how it is called below); it returns a new object whose fields (in the order they were specified) are bound to the values in the interable (in that same order). For example, if we called Point._make((0,1)) the result returned is a new Point object whose x attribute is bound to 0 and whose y attribute is bound to 1.