code: protected OAuthRegisteredService getOAuthRegisteredServiceBy(final HttpServletRequest request) {
          val redirectUri = getRegisteredServiceIdentifierFromRequest(request);
          val registeredService = OAuth20Utils.getRegisteredOAuthServiceByRedirectUri(getOAuthConfigurationContext().getServicesManager(), redirectUri);
          LOGGER.debug("Located registered service [{}]", registeredService);
          return registeredService;
      }
docs: Gets oauth registered service from the request.
  Implementation attempts to locate the redirect uri from request and
  check with service registry to find a matching oauth service.
  
  @param request the request
  @return the registered service