code: function addonsManager_getAddonChildElement(aSpec) {
      var spec = aSpec || { };
      var addon = spec.addon;
      var attribute = spec.attribute;
      var value = spec.value;
      var type = spec.type;
  
      if (!addon)
        throw new Error(arguments.callee.name + ": Add-on not specified.");
  
      // If no type has been set retrieve a general element which needs an
      // attribute and value
      if (!type) {
        type = "element";
  
        if (!attribute)
          throw new Error(arguments.callee.name + ": DOM attribute not specified.");
        if (!value)
          throw new Error(arguments.callee.name + ": Value not specified.");
      }
  
      // For the details view the elements don't have anonymous nodes
      if (this.selectedView.getNode().id == "detail-view") {
        return this.getElement({
          type: "detailView_" + type,
          subtype: attribute,
          value: value
        });
      } else {
        return this.getElement({
          type: "listView_" + type,
          subtype: attribute,
          value: value,
          parent: addon
        });
      }
    }
docs: Retrieve the given child element of the specified add-on
  
  @param {object} aSpec
  Information for getting the add-ons child node
  Elements: addon     - Add-on element
  type      - Type of the element
  [optional - default: use attribute/value]
  attribute - DOM attribute of the node
  value     - Value of the DOM attribute
  
  @returns Element
  @type {ElemBase}