old_contents: (function (Modules) {
    "use strict";
  
    Modules.DeselectTaxonClick = function () {
      var helper = window.GOVUK.taxonomyTreeHelper;
      this.start = function (container) {
        var deselectTaxonClick = function () {
          var taxon_name = $(container).closest('.taxon-breadcrumb').find('li:last').text() ;
          $("input[data-taxon-name=\"" + taxon_name + "\"]").each(function(idx, el){
            $(el).prop('checked', false);
            if (!helper.hasCheckedSiblings(el)){
              helper.uncheckAncestors(el);
            }
          });
          $('.topic-tree').trigger('change');
          return false;
        };
  
        container.on("click", deselectTaxonClick);
      };
    };
  
  })(window.GOVUKAdmin.Modules);
  
new_contents: (function (Modules) {
    "use strict";
  
    Modules.DeselectTaxonClick = function () {
      var taxonomyTreeHelper = window.GOVUK.taxonomyTreeHelper;
      this.start = function (container) {
        var deselectTaxonClick = function () {
          var taxon_name = $(container).closest('.taxon-breadcrumb').find('li:last').text() ;
          $("input[data-taxon-name=\"" + taxon_name + "\"]").each(function(idx, el){
            $(el).prop('checked', false);
            if (!taxonomyTreeHelper.hasCheckedSiblings(el)){
              taxonomyTreeHelper.uncheckAncestors(el);
            }
          });
          $('.topic-tree').trigger('change');
          return false;
        };
  
        container.on("click", deselectTaxonClick);
      };
    };
  
  })(window.GOVUKAdmin.Modules);
  
subject: Rename helper to taxonomyTreeHelper