ning with the
            one whose length is <code>A1</code>'s <a href=
            "overloads.html#overload-dispatch-expression"><em>minimum
            arity</em></a>, adds a
            <code><em>name</em>(</code>...<code>)</code> method overload to
            the extension class. Each overload generated invokes
            <code>a1</code>'s call-expression with <em>P</em>, using a copy
            of <code>a1</code>'s <a href="CallPolicies.html">call
            policies</a>. If the longest valid pref