code: public static Value get( H2ONode target, Key key, int priority ) {
      RPC<TaskGetKey> rpc, old;
      while( true ) {       // Repeat until we get a unique TGK installed per key
        // Do we have an old TaskGetKey in-progress?
        rpc = TGKS.get(key);
        if( rpc != null && rpc._dt._priority >= priority )
          break;
        old = rpc;
        // Make a new TGK.
        rpc = new RPC(target,new TaskGetKey(key,priority),1.0f);
        if( TGKS.putIfMatchUnlocked(key,rpc,old) == old ) {
          rpc.setTaskNum().call(); // Start the op
          break;                  // Successful install of a fresh RPC
        }
      }
      Value val = rpc.get()._val; // Block for, then fetch out the result
      TGKS.putIfMatchUnlocked(key,null,rpc); // Clear from cache
      return val;
    }
docs: Get a value from a named remote node