code: @Override public void dinvoke( H2ONode sender ) {
      _h2o = sender;
      Key k = _key;
      _key = null;          // Not part of the return result
      assert k.home();      // Gets are always from home (less we do replication)
      // Shipping a result?  Track replicas so we can invalidate.  There's a
      // narrow race on a moving K/V mapping tracking this Value just as it gets
      // deleted - in which case, simply retry for another Value.
      do  _val = H2O.get(k);      // The return result
      while( _val != null && !_val.setReplica(sender) );
      tryComplete();
    }
docs: Top-level non-recursive invoke