code: public Node getNode(String loc) {
      netlock.readLock().lock();
      try {
        loc = NodeBase.normalize(loc);
        if (!NodeBase.ROOT.equals(loc))
          loc = loc.substring(1);
        return clusterMap.getLoc(loc);
      } finally {
        netlock.readLock().unlock();
      }
    }
docs: Given a string representation of a node, return its reference
  
  @param loc
  a path-like string representation of a node
  @return a reference to the node; null if the node is not in the tree