ant"})
  })
}, 'IntersectionObserver constructor with { rootMargin: "1px !important" }');

test(function () {
  assert_throws_dom("SYNTAX_ERR", function() {
    new IntersectionObserver(e => {}, {rootMargin: "1px 1px 1px 1px 1px"})
  })
}, 'IntersectionObserver constructor with { rootMargin: "1px 1px 1px 1px 1px" }');

test(function () {
  assert_throws_js(TypeError, function() {
    let observer = new IntersectionObserver(c => {}, {});
    observer.observe("foo");
  })
}, 'IntersectionObserver.observe("foo