public void onResponse(DiscoveryNode node){
  boolean found=pendingNodes.remove(node);
  assert found : "node [" + node + "] already responded or failed";
  latch.countDown();
}

public void onResponse ( DiscoveryNode node ) { boolean found = pendingNodes . remove ( node ) ; assert found : "node [" + node + "] already responded or failed" ; latch . countDown ( ) ; }
called for each response obtained from non master nodes
