public String getButtonNameMap() {
  Map buttonNameMap = new Map();
  for(LiveChatButton chatButton:[SELECT DeveloperName FROM LiveChatButton WHERE DeveloperName =:buttonNamesSet LIMIT :Limits.getLimitQueryRows() - Limits.getQueryRows()] ) {
    buttonNameMap.put(chatButton.DeveloperName,chatButton.Id); 
   }
   return JSON.serialize(buttonNameMap);
}