private OAuth2SpecInfo lookupSpecInfo(final SecurityToken securityToken,
      final OAuth2Arguments arguments, final Uri gadgetUri) throws OAuth2RequestException {
    log.entering(CLASS, "lookupSpecInfo", new Object[] { securityToken, arguments, gadgetUri });
    final GadgetSpec spec = this.findSpec(securityToken, arguments, gadgetUri);
    final OAuth2Spec oauthSpec = spec.getModulePrefs().getOAuth2Spec();
    if (oauthSpec == null) {
      throw new OAuth2RequestException(OAuth2Error.LOOKUP_SPEC_PROBLEM,
          "Failed to retrieve OAuth URLs, spec for gadget " + securityToken.getAppUrl()
          + " does not contain OAuth element.", null);
    }