code: function(msg, ioNs, node, socketId) {
          if (socketId) msg._socketId = socketId
  
          // Send to specific client if required
          if (msg._socketId) ioNs.to(msg._socketId).emit(node.ioChannels.control, msg)
          else ioNs.emit(node.ioChannels.control, msg)
  
          if ( (! msg.hasOwnProperty('topic')) && (node.topic !== '') ) msg.topic = node.topic
  
          // copy msg to output port #2
          node.send([null, msg])
      }
docs: ---- End of getProps ---- // Output a control msg
  Sends to all connected clients & outputs a msg to port 2
  @param {Object} msg The message to output
  @param {Object} ioNs Socket.IO instance to use
  @param {Object} node The node object
  @param {string=} socketId Optional. If included, only send to specific client id