 each <code>logentry</code>. A set of expressions controls the mapping from Istio attributes and literal values into the values that constitute a <code>logentry</code>. In this example, each <code>logentry</code> instance has a field named <code>latency</code> populated with the value from the attribute <code>response.duration</code>. If there is no known value for <code>response.duration</code>, the <code>latency</code> field will be set to a duration of <code>0ms</code>.</p><p>The <code>kind: stdio</code>