mon expressions, which means you
must double-quote strings in JSON, e.g. &ldquo;&lsquo;string value&rsquo;&rdquo;. Unlike Mixer
expression language, there is no support for the pipe (<code>|</code>) operator, but you
can emulate it with the <code>has</code> or <code>in</code> operator, for example:</p><pre><code class=language-plain data-expandlinks=true data-repo=istio>has(request.host) ? request.host : &#34;unknown&#34;
</code></pre><p>For more information, see <a href=https://opensource.google/projects/c