def remove_cohort(self, institute, case, user, link, tag):
self.create_event(<EOL>institute=institute,<EOL>case=case,<EOL>user=user,<EOL>link=link,<EOL>category='<STR_LIT>',<EOL>verb='<STR_LIT>',<EOL>subject=case['<STR_LIT>'],<EOL>)<EOL>LOG.info("<STR_LIT>"<EOL>.format(tag, case['<STR_LIT>']))<EOL>updated_case = self.case_collection.find_one_and_update(<EOL>{'<STR_LIT>': case['<STR_LIT>']},<EOL>{<EOL>'<STR_LIT>': {'<STR_LIT>': tag},<EOL>},<EOL>return_document=pymongo.ReturnDocument.AFTER<EOL>)<EOL>LOG.debug("<STR_LIT>")<EOL>return updated_case<EOL>
Remove a cohort tag from case

        Arguments:
            institute (dict): A Institute object
            case (dict): Case object
            user (dict): A User object
            link (str): The url to be used in the event
            tag (str): The cohort tag to be removed

        Return:
            updated_case(dict)