/**
  * Read gcm key
  *
  * @param coreXML
  * @return gcm key
  */
 public String readGCMKey(CoreXMLHandler coreXML) {
   String gcmKey = null;
   try {
     gcmKey = coreXML.getGcmKey();
   } catch (Exception ex) {
     ex.printStackTrace();
   }
   return gcmKey;
 }
 /**
  * Read core url
  *
  * @param coreXML
  * @return url
  */
 public String readUrl(CoreXMLHandler coreXML) {
   String url = null;
   try {
     url = coreXML.getUrl();
   } catch (Exception ex) {
     ex.printStackTrace();
   }
   return url;
 }