function assert_header_equals(value, expected, tag) {
  if (typeof(value) === "string"){
    assert_not_equals(value, "No header has been recorded");
    value = JSON.parse(value);
  }

  test(t => assert_equals(value.dest, expected.dest), `${tag}: sec-fetch-dest`);
  test(t => assert_equals(value.mode, expected.mode), `${tag}: sec-fetch-mode`);
  test(t => assert_equals(value.site, expected.site), `${tag}: sec-fetch-site`);
  test(t => assert_equals(value.user, expected.user), `${tag}: sec-fetch-user`);
}
@param {object} value
@param {object} expected
@param {string} tag