anchor.diff:        return this
       }
       ConfSite.prototype.addConference = function addConference(conf_label, conference) {
  -      this.conferences.push({ _key: conf_label, _value: conference })
  +      this.conferences[conf_label] = conference
         return this
       }
       ConfSite.prototype.removeConference = function removeConference(conf_label) {
  
positive.code:     ConfSite.prototype.getLogo = function getLogo() {
        return this.logo
      }
      ConfSite.prototype.getConference = function getConference(conf_label, with_key) {
        var returned = this.conferences.find(function (item) { return item._key === conf_label })
        return (with_key) ? returned : (returned || {})._value
      }
      ConfSite.prototype.getCurrentConference = function getCurrentConference() {
        return this.conferences[this.conference_current_index]._value
      }
      ConfSite.prototype.getPrevConference = function getPrevConference() {
        return this.conferences[this.conference_prev_index]._value
      }
      ConfSite.prototype.getNextConference = function getNextConference() {
        return this.conferences[this.conference_next_index]._value
      }
      ConfSite.prototype.getSupporterLevel = function getSupporterLevel(supporter_level_name) {
        return this.supporter_levels.find(function (item) { return item.name === supporter_level_name })
  
negative.code:       return this
      }
      ConfSite.prototype.setCurrentConference = function setCurrentConference(conf_label) {
        this._conference_current_index = conf_label
        this.initializeMainPages()
        return this
      }
      ConfSite.prototype.setPrevConference = function setPrevConference(conf_label) {
        this._conference_prev_index = conf_label
        return this
      }
      ConfSite.prototype.setNextConference = function setNextConference(conf_label) {
        this._conference_next_index = conf_label
        return this
      }
      ConfSite.prototype.addSupporterLevel = function addSupporterLevel(supporter_level) {
  