function rewire(filename) {
    return rewireModule(module.parent, filename);
}
Adds a special setter and getter to the module located at filename. After the module has been rewired, you can
call myModule.__set__(name, value) and myModule.__get__(name) to manipulate private variables.

@param {!String} filename Path to the module that shall be rewired. Use it exactly like require().
@return {*} the rewired module