code: void performStreamingRepair()
      {
          InetAddress local = FBUtilities.getBroadcastAddress();
          // We can take anyone of the node as source or destination, however if one is localhost, we put at source to avoid a forwarding
          InetAddress src = r2.endpoint.equals(local) ? r2.endpoint : r1.endpoint;
          InetAddress dst = r2.endpoint.equals(local) ? r1.endpoint : r2.endpoint;
  
          SyncRequest request = new SyncRequest(desc, local, src, dst, differences);
          StreamingRepairTask task = new StreamingRepairTask(desc, request);
          task.run();
      }
docs: Starts sending/receiving our list of differences to/from the remote endpoint: creates a callback
  that will be called out of band once the streams complete.