code: private Map<String, String> getHttpHeaderStrong() throws Exception {
          
          final OAuthToken token = root.getOAuthTokenManager().getToken();
          
          if (token == null || token.getAccessToken().length() == 0 || token.getTokenType().length() == 0)
              throw new Exception ("OAuth token is not created (or is invalid) for strong authentication");
                  
          return new HashMap<String, String>(){{
              put("Authorization", token.getTokenType() + " " + token.getAccessToken());
          }};
      }
docs: gets HTTP header value with authorization string for strong authentication