/** * Sends optional message. If message is {@code null} - it's no-op. * * @param nodeId ID of the node to send message to. * @param respMsg Message to send. * @throws GridException Thrown in case of any errors. */ private void send(UUID nodeId, @Nullable Object respMsg) throws GridException { assert nodeId != null; if (respMsg != null) { GridNode node = grid.node(nodeId); if (node != null) grid.forNode(node).message().send(null, respMsg); // Can still fail. else throw new GridException( "Failed to send message since destination node has " + "left topology (ignoring) [nodeId=" + nodeId + ", respMsg=" + respMsg + ']'); } }