/*
   * Set the authentication method
   *
   * Value must be one of:
   * * Openwsman::NO_AUTH_STR
   * * Openwsman::BASIC_AUTH_STR
   * * Openwsman::DIGEST_AUTH_STR
   * * Openwsman::PASS_AUTH_STR
   * * Openwsman::NTLM_AUTH_STR
   * * Openwsman::GSSNEGOTIATE_AUTH_STR
   *
   */
  void set_auth_method(const char *am) {