docs: public ClientVpnEndpoint withAuthenticationOptions(ClientVpnAuthentication... authenticationOptions) {
          if (this.authenticationOptions == null) {
              setAuthenticationOptions(new com.amazonaws.internal.SdkInternalList<ClientVpnAuthentication>(authenticationOptions.length));
          }
          for (ClientVpnAuthentication ele : authenticationOptions) {
              this.authenticationOptions.add(ele);
          }
          return this;
      }