">ErrExtensionUnsupported</span></span> <span class="p">=</span> <a href="https://pkg.go.dev/errors"><span class="nx">errors</span></a><span class="p">.</span><a href="https://pkg.go.dev/errors#New"><span class="nf">New</span></a><span class="p">(</span><span class="s">&#34;agent: extension unsupported&#34;</span><span class="p">)</span></pre>
  <p>ErrExtensionUnsupported indicates that an extension defined in
[PROTOCOL.agent] section 3.8 is unsupported by the agent. Specifically this
error indicates that t