iteration, that it's reified
// as a CSSUnparsedValue, and that the string representation is equal to
// 'value'.
function verify_map_iteration_unparsed(map, name, value) {
    map.set(name, value);
    let result = Array.from(map).filter(e => e[0] == name)[0];
    assert_equals(result.length, 2);
    let iter_value = result[1];
    assert_equals(iter_value.length, 1);
    assert_true(iter_value[0] instanceof CSSUnparsedValue);
    assert_equals(iter_value[0].toString(), value);
}

// Verifies that CSSStyle