an>
    <span class="nx">method?</span>: <span class="kt">string</span><span class="p">;</span>
    <span class="nx">headers?</span>: <span class="kt">HeadersInit</span> <span class="o">|</span> <span class="p">{</span> <span class="p">[</span><span class="nx">index</span>: <span class="kt">string</span><span class="p">]</span><span class="o">:</span> <span class="kt">string</span> <span class="p">};</span>
    <span class="nx">body?</span>: <span class="kt">BodyInit</span><span class="p">;</span>
    <span