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<html>
  <head>
    <title>XMLHttpRequest: response is plain text if responseType is set to an invalid string</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <link rel="help" href="https://xhr.spec.whatwg.org/#the-response-attribute" data-tested-assertations="following::dd[2]/ol[1]/li[2]" />
    <link rel="help" href="https://xhr.spec.whatwg.org/#the-responsetype-attribute" data-tested-assertations="following::ol[1