-line-signature">
          <a href="https://api.flutter.dev/flutter/dart-core/Map-class.html">Map</a><span class="signature">&lt;<wbr><span class="type-parameter"><a href="https://api.flutter.dev/flutter/dart-core/String-class.html">String</a></span>, <span class="type-parameter"><a href="https://api.flutter.dev/flutter/dart-core/String-class.html">String</a></span>&gt;</span>?
          <span class="name ">headers</span>
          <div class="features">final</div>

        </section>
        
<section cla