async function testBasicUpdate(
        firstLines, firstReferences, secondLines, secondReferences) {
      const firstManifest = makeSimpleLiveManifestText(firstLines, updateTime);
      const secondManifest =
          makeSimpleLiveManifestText(secondLines, updateTime);

      fakeNetEngine.setResponseText('dummy://foo', firstManifest);
      const manifest = await parser.start('dummy://foo', playerInterface);
      const stream = manifest.variants[0].video;
      await stream.createSegmentIndex();
      ManifestParser.verifySegmentIndex(stream, firstReferences);

      fakeNetEngine.setResponseText('dummy://foo', secondManifest);
      await updateManifest();
      ManifestParser.verifySegmentIndex(stream, secondReferences);
    }
Tests that an update will show the given references.

@param {!Array<string>} firstLines The Representation contents for the
  first manifest.
@param {!Array<!shaka.media.SegmentReference>} firstReferences The media
  references for the first parse.
@param {!Array<string>} secondLines The Representation contents for the
  updated manifest.
@param {!Array<!shaka.media.SegmentReference>} secondReferences The
  media references for the updated manifest.