code: function(mediator) {
  
      //If there is already a set of subscribers set up, then don't subscribe again.
      if (workorderSubscribers) {
        return workorderSubscribers;
      }
  
      workorderSubscribers = new MediatorTopicUtility(mediator);
      workorderSubscribers.prefix(CONSTANTS.TOPIC_PREFIX).entity(CONSTANTS.WORKORDER_ENTITY_NAME);
  
      //Setting up subscribers to the workorder topics.
      _.each(CONSTANTS.TOPICS, function(topicName) {
        if (topicHandlers[topicName]) {
          workorderSubscribers.on(topicName, topicHandlers[topicName](workorderSubscribers));
        }
      });
  
      return workorderSubscribers;
    }
docs: Initialisation of all the topics that this module is interested in.
  @param mediator
  @returns {Topics|exports|module.exports|*}