Add @override, remove @attribute/@group/@hero/@homepage

lib/elements/dom-module.js

@@ -70,6 +70,7 @@ function styleOutsideTemplateCheck(inst) {
  */
 export class DomModule extends HTMLElement {
 
+  /** @override */
   static get observedAttributes() { return ['id']; }
 
   /**

lib/legacy/legacy-element-mixin.js

@@ -519,6 +519,7 @@ export const LegacyElementMixin = dedupingMixin((base) => {
      * @this {Element}
      * @return {?Node} The element whose local dom within which this element is
      * contained.
+     * @override
      */
     get domHost() {
       let root = wrap(this).getRootNode();

lib/legacy/mutable-data-behavior.js

@@ -70,6 +70,7 @@ export const MutableDataBehavior = {
    * @param {*} old Previous property value
    * @return {boolean} Whether the property should be considered a change
    * @protected
+   * @override
    */
   _shouldPropertyChange(property, value, old) {
     return mutablePropertyChange(this, property, value, old, true);
@@ -142,6 +143,7 @@ export const OptionalMutableDataBehavior = {
    * @param {*} old Previous property value
    * @return {boolean} Whether the property should be considered a change
    * @protected
+   * @override
    */
   _shouldPropertyChange(property, value, old) {
     return mutablePropertyChange(this, property, value, old, this.mutableData);

lib/mixins/element-mixin.js

@@ -370,6 +370,7 @@ export const ElementMixin = dedupingMixin(base => {
         }
       }
 
+      /** @override */
       this.prototype._template = template;
     }
 

lib/utils/templatize.js

@@ -300,6 +300,7 @@ class TemplateInstanceBase extends templateInstanceBase {
    *
    * @param {Event} event Event to dispatch
    * @return {boolean} Always true.
+   * @override
    */
    dispatchEvent(event) { // eslint-disable-line no-unused-vars
      return true;