CODEOWNERS per line ownership

We work with some files owned by multiple teams in CODEOWNERS file. Example:
path/to/file @my-team @not-my-team
However, the separation within the file is clear and we’d like to own code on a line basis instead of a file basis. I don’t think this is currently possible (is it?) but perhaps a solution like this would work:
path/to/file:12:56 @my-team
An alternative is either a) split the file or b) introduce another ownership system. Both are not great solutions.