code: public void sendBroadcast(CmsObject cms, String message, boolean repeat) {
  
          if (CmsStringUtil.isEmptyOrWhitespaceOnly(message)) {
              // don't broadcast empty messages
              return;
          }
          // create the broadcast
          CmsBroadcast broadcast = new CmsBroadcast(cms.getRequestContext().getCurrentUser(), message, repeat);
          // send the broadcast to all authenticated sessions
          Iterator<CmsSessionInfo> i = m_sessionStorageProvider.getAll().iterator();
          while (i.hasNext()) {
              CmsSessionInfo sessionInfo = i.next();
              if (m_sessionStorageProvider.get(sessionInfo.getSessionId()) != null) {
                  // double check for concurrent modification
                  sessionInfo.getBroadcastQueue().add(broadcast);
              }
          }
  
      }
docs: Sends a broadcast to all sessions of all currently authenticated users.<p>
  
  @param cms the OpenCms user context of the user sending the broadcast
  
  @param message the message to broadcast
  @param repeat repeat this message