Get block id in block theme template I'd like to be able to print the block id/number of my custom block in its template. I feel like these must exist because Display Suite has a token for it: [block_content:id]. 

Like a url to edit a block is, it goes to the edit form: block/17

How do I get that 17 in the twig template? Looking in block.html.twig, I don't see anything about a block's number.
You find the block_content entity in the template variable elements to get the ID:

block.html.twig:

{{ elements.content['#block_content'].id() }}