    def user_lookup_by_name(self, username):
        # type: (str) -> User
        '''
        Looks up a user by their username.

        Args:
            username (str): The username of the user to look up.
        Resturns:
            (dict): All known information about that user.
        '''
        if username not in self.users_by_name:
            raise SecurityBotException('User {} not found'.format(username))
        return self.users_by_name[username]
Looks up a user by their username.

Args:
username (str): The username of the user to look up.
Resturns:
(dict): All known information about that user.
securitybot/bot.py