def update_sasl(disable, user, pass)
      @sasl_username = valid! user, valid_string(user), :@sasl_username,
                              invalid_error: 'invalid SASL username %s'
      @sasl_password = valid! pass, valid_string(pass), :@sasl_password,
                              invalid_error: 'invalid SASL password %s'
      return unless disable

      @sasl_username = nil
      @sasl_password = nil
    end
def update_sasl(disable, user, pass)
      @sasl_username = valid! user, valid_string(user), :@sasl_username,
                              invalid_error: 'invalid SASL username %s'
      @sasl_password = valid! pass, valid_string(pass), :@sasl_password,
                              invalid_error: 'invalid SASL password %s'
      return unless disable

      @sasl_username = nil
      @sasl_password = nil
    end
Updates the SASL authentication details of this network.

 @param disable [Boolean] whether to disable SASL, or +nil+ to keep the
                          current value.
 @param user [String] the SASL username, or +nil+ to keep the current value
 @param pass [String] the SASL password, or +nil+ to keep the current value