code: private RevocationResponse callRevocation(String parameters, String clientId, String clientSecret)
      {
          if (parameters == null)
          {
              // Authlete returns different error codes for null and an empty string.
              // 'null' is regarded as a caller's error. An empty string is regarded
              // as a client application's error.
              parameters = "";
          }
  
          // Create a request for Authlete's /api/auth/revocation API.
          RevocationRequest request = new RevocationRequest()
              .setParameters(parameters)
              .setClientId(clientId)
              .setClientSecret(clientSecret);
  
          try
          {
              // Call Authlete's /api/auth/revocation API.
              return mApi.revocation(request);
          }
          catch (AuthleteApiException e)
          {
              // The API call failed.
              throw apiFailure("/api/auth/revocation", e);
          }
      }
docs: Call Authlete's {@code /api/auth/revocation} API.