1. resizeobserver api

2. resizeobserverentry api

3. resizeobserverentry api: borderboxsize

4. resizeobserverentry api: contentboxsize

5. resizeobserverentry api: contentrect

6. resizeobserverentry api: devicepixelcontentboxsize

7. resizeobserverentry api: target

8. resizeobserversize api

9. resizeobserversize api: blocksize

10. resizeobserversize api: inlinesize

11. resizeobserver api: disconnect

12. resizeobserver api: observe

13. resizeobserver api: observe: `options.box` parameter

14. resizeobserver api: `resizeobserver()` constructor

15. resizeobserver api: unobserve