How to modify Twitter Bootstrap collapse plugin to keep accordions open

Since the question didn't refer to a specific version of Bootstrap, here's a bootstrap 4 solution: Remove the data-parent="#accordion" from the tags with the data-toggle="collapse" attribute. It's the example taken from the Collapse documentation with the data-parent=#accordion" bit taken out.

Source: https://stackoverflow.com/questions/10019689/modify-twitter-bootstrap-co...