code: public synchronized boolean tryDelegateSlop(Node node) {
          if(asyncCallbackShouldSendhint) {
              return false;
          } else {
              slopDestinations.put(node, true);
              return true;
          }
      }
docs: Try to delegate the responsibility of sending slops to master
  
  @param node The node that slop should eventually be pushed to
  @return true if master accept the responsibility; false if master does
  not accept