code: @SuppressWarnings("WeakerAccess")
      public Request<Void, AuthenticationException> revokeToken(@NonNull String refreshToken) {
          final Map<String, Object> parameters = ParameterBuilder.newBuilder()
                  .setClientId(getClientId())
                  .set(TOKEN_KEY, refreshToken)
                  .asDictionary();
  
          HttpUrl url = HttpUrl.parse(auth0.getDomainUrl()).newBuilder()
                  .addPathSegment(OAUTH_PATH)
                  .addPathSegment(REVOKE_PATH)
                  .build();
  
          return factory.POST(url, client, gson, authErrorBuilder)
                  .addParameters(parameters);
      }
docs: Request the revoke of a given refresh_token. Once revoked, the refresh_token cannot be used to obtain new tokens.
  The client must be of type 'Native' or have the 'Token Endpoint Authentication Method' set to 'none' for this endpoint to work.
  Example usage:
  <pre>
  {@code
  client.revokeToken("{refresh_token}")
  .start(new BaseCallback<Void>() {
  {@literal}Override
  public void onSuccess(Void payload) {}
  
  {@literal}Override
  public void onFailure(AuthenticationException error) {}
  });
  }
  </pre>
  
  @param refreshToken the token to revoke
  @return a request to start