f <var>map</var> does not have a <emu-const><var class="field">[[MapData]]</var></emu-const> internal slot, throw a <emu-val>TypeError</emu-val> exception.</li></ol></li><li>Let <var>entries</var> be the List that is <var>map</var>.<var class="field">[[MapData]]</var>.</li><li>For each Record { <var class="field">[[Key]]</var>, <var class="field">[[Value]]</var>&nbsp;} <var>e</var> that is an element of <var>entries</var>, in original key insertion order, do:<ol><li>If <var>e</var>.<var class="field">[[Key]