<!DOCTYPE html><metacharset=utf-8><title>DocumentTimeline.duration</title><linkrel="help"href="https://drafts.csswg.org/web-animations-2/#dom-animationtimeline-duration"><scriptsrc="/resources/testharness.js"></script><scriptsrc="/resources/testharnessreport.js"></script><scriptsrc="../../testcommon.js"></script><scriptsrc="../../resources/timing-override.js"></script><body><divid="log"></div><script>'use strict';test(t=>{consttimeline=newDocumentTimeline();assert_equals(timeline.duration,null);},'A document timeline does not have a duration');</script></body>