def query_users_from_emails(self, emails):
        usernames = []
        for e in emails:
            next_username = None
            for u in self._data.users:
                if u.email == e:
                    next_username = u.username
            usernames.append(next_username)
        return usernames
Return a list of username strings based on the provided emails.
dataset/ETHPy150Open bloomberg/phabricator-tools/py/abd/abdt_conduitmock.py/ConduitMock.query_users_from_emails