/**
  * Use cursors to fetch upto jtwit.maxResults TODO More controlled paging??
  *
  * @param url API method to call
  * @param screenName
  * @param userId
  * @return twitter-id numbers for friends/followers of screenName or userId Is affected by {@link
  *     #maxResults}
  */
 private List<Number> getUserIDs(String url, String screenName, Long userId) {
   Long cursor = -1L;
   List<Number> ids = new ArrayList<Number>();
   if (screenName != null && userId != null)
     throw new IllegalArgumentException(
         "cannot use both screen_name and user_id when fetching user_ids");
   Map<String, String> vars = InternalUtils.asMap("screen_name", screenName, "user_id", userId);
   while (cursor != 0 && !jtwit.enoughResults(ids)) {
     vars.put("cursor", String.valueOf(cursor));
     String json = http.getPage(url, vars, http.canAuthenticate());
     try {
       // it seems Twitter will occasionally return a raw array
       JSONArray jarr;
       if (json.charAt(0) == '[') {
         jarr = new JSONArray(json);
         cursor = 0L;
       } else {
         JSONObject jobj = new JSONObject(json);
         jarr = (JSONArray) jobj.get("ids");
         cursor = new Long(jobj.getString("next_cursor"));
       }
       for (int i = 0; i < jarr.length(); i++) {
         ids.add(jarr.getLong(i));
       }
       if (jarr.length() == 0) {
         // No more
         break;
       }
     } catch (JSONException e) {
       throw new TwitterException.Parsing(json, e);
     }
   }
   return ids;
 }
 /**
  * @return an array of numeric user ids the authenticating user is blocking. Use {@link
  *     #showById(Collection)} if you want to convert thse into User objects.
  */
 public List<Number> getBlockedIds() {
   String json = http.getPage(jtwit.TWITTER_URL + "/blocks/ids.json", null, true);
   try {
     JSONArray arr =
         json.startsWith("[") ? new JSONArray(json) : new JSONObject(json).getJSONArray("ids");
     List<Number> ids = new ArrayList(arr.length());
     for (int i = 0, n = arr.length(); i < n; i++) {
       ids.add(arr.getLong(i));
     }
     return ids;
   } catch (JSONException e) {
     throw new TwitterException.Parsing(json, e);
   }
 }