mport url("nonexist.css") layer supports(foo: bar);');
  test_valid_supports_import('@import url("nonexist.css") layer(A) supports((display: flex) or (foo: bar));');
  test_valid_supports_import('@import url("nonexist.css") layer(A.B) supports((display: flex) and (foo: bar));');

  test_valid_supports_import('@import url("nonexist.css") supports(selector(a));');
  test_valid_supports_import('@import url("nonexist.css") supports(selector(p a));');
  test_valid_supports_import('@import url("nonexist.css") sup