mu-val>TypeError</emu-val> exception.</li></ol></li><li>If IsCallable(<var>callbackfn</var>) is false, throw a <emu-val>TypeError</emu-val> exception.</li><li>If <var>thisArg</var> was supplied, let <var>T</var> be <var>thisArg</var>; else let <var>T</var> be <emu-val>undefined</emu-val>.</li><li>Let <var>Ctr</var> be ?&nbsp;SpeciesConstructor(<var>map</var>, %Map%)</li><li>Let <var>newMap</var> be ?&nbsp;Construct(<var>Ctr</var>)</li><li>Let <var>adder</var> be ?&nbsp;Get(<var>newSet</var>, "set")<ol><li>I