code: function uniqueIdentifier( ) {
      return Math.floor(Math.random() * 1000000).toString(36).toUpperCase() + (new Date).getTime().toString(36).toUpperCase();
  }
docs: /* uniqueIdentifier
  Used to create a unique identifiers for use in x-stream-origin header value, so that in a duplex
  amqp stream, write will not emit messages locally, and for correlation ID's.