def opt_user(self, user_pass):
        try:
            user, password = user_pass.split('=', 1)
        except ValueError:
            raise usage.UsageError("Argument to --user must be of the form 'user=password'")
        if self.last_domain:
            self.last_domain.addUser(user, password)
        else:
            raise usage.UsageError("Specify a domain before specifying users")
add a user/password to the last specified domains
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/mail/tap.py/Options.opt_user