A cursory inspection of get_bug_tags_open_count in lib/lp/bugs/model/bug.py seems to indicate that the results of an SQL query are just returned so perhaps that would return {count}?
A cursory inspection of get_bug_ tags_open_ count in lib/lp/ bugs/model/ bug.py seems to indicate that the results of an SQL query are just returned so perhaps that would return {count}?