A template result can extend another:
"css....extends(...)" will join them.
"html....extends(...)" is different, see the comments below.
For html or svg template the extends will merge root attributes and slot elements into super,
so you can reuse super rendering result and add some classes or styles and set same slots,
Join strings and values to string. Just for debugging.
Generated using TypeDoc
Created from each html
...or svg.... Every time callcomponent.updatewill generate a new template result, then we will use this result to merge or replaced old one.