Translation of "adaptee" into French

A class that is converted to another class using a so-called adapter class.“Head First Design Patterns”, in (Please provide the title of the work) ^[1] (paperback, in English), volume 1, O'REILLY, 2004, retrieved 2012-07-02, page 242: “The Adapter Pattern's role is to convert one interface into another. While most examples of the dapter pattern show an adapter wrapping one adaptee, we both know the World is often a bit more messy. So, you may well have situation where an adapter holds two or more adaptees that are needed to implement the target interface.”