 href="dart-io/X509Certificate-class.html">X509Certificate</a></span> <span class="parameter-name">certificate</span></span>)</span> })
            <span class="returntype parameter">&#8594; <a href="dart-async/Future-class.html">Future</a><span class="signature">&lt;<a href="dart-io/SecureSocket-class.html">SecureSocket</a>&gt;</span></span>
          </span>
        </dt>
        <dd>
          Takes an already connected <code>socket</code> and starts client side TLS
handshake to make the communication se