">&#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 server side TLS
handshake to make the communication secure. When the returned
future completes the <a href="dart-io/SecureSocket-class.html">SecureSocket</a> has completed the TLS
handshake. Using this function requires that the other 