diff --git a/frontend/src/core/utility.js b/frontend/src/core/utility.js
index 6b74920dd..dba52923a 100644
--- a/frontend/src/core/utility.js
+++ b/frontend/src/core/utility.js
@@ -3,7 +3,7 @@ export function isValidUtility(utility) {
     return false;
   }
 
-  if (Utility.selector) {
+  if (!utility.selector) {
     return false;
   }
 
diff --git a/frontend/src/utils/asidenav/asidenav.js b/frontend/src/utils/asidenav/asidenav.js
index 09d295063..3b5c048ff 100644
--- a/frontend/src/utils/asidenav/asidenav.js
+++ b/frontend/src/utils/asidenav/asidenav.js
@@ -14,6 +14,7 @@ const ASIDENAV_SUBMENU_CLASS = 'asidenav__nested-list-wrapper';
 export class Asidenav {
 
   _element;
+  _asidenavSubmenus;
 
   constructor(element) {
     if (!element) {
@@ -34,12 +35,14 @@ export class Asidenav {
   }
 
   destroy() {
-    console.log('TBD: Destroy Asidenav');
+    this._asidenavSubmenus.forEach((union) => {
+      union.listItem.removeEventListener(union.hoverHandler);
+    });
   }
 
   _initFavoritesButton() {
     const favoritesBtn = document.querySelector('.' + FAVORITES_BTN_CLASS);
-    favoritesBtn.addEventListener('click', function(event) {
+    favoritesBtn.addEventListener('click', (event) => {
       favoritesBtn.classList.toggle(FAVORITES_BTN_ACTIVE_CLASS);
       this._element.classList.toggle(ASIDENAV_EXPANDED_CLASS);
       event.preventDefault();
@@ -47,7 +50,7 @@ export class Asidenav {
   }
 
   _initAsidenavSubmenus() {
-    const asidenavLinksWithSubmenus = Array.from(this._element.querySelectorAll('.' + ASIDENAV_LIST_ITEM_CLASS))
+    this._asidenavSubmenus = Array.from(this._element.querySelectorAll('.' + ASIDENAV_LIST_ITEM_CLASS))
       .map(function(listItem) {
         const submenu = listItem.querySelector('.' + ASIDENAV_SUBMENU_CLASS);
         return { listItem, submenu };
@@ -55,13 +58,14 @@ export class Asidenav {
         return union.submenu !== null;
       });
 
-    asidenavLinksWithSubmenus.forEach(function(union) {
-      union.listItem.addEventListener('mouseover', this.createMouseoverHandler(union));
+    this._asidenavSubmenus.forEach((union) => {
+      union.hoverHandler = this._createMouseoverHandler(union);
+      union.listItem.addEventListener('mouseover', union.hoverHandler);
     });
   }
 
   _createMouseoverHandler(union) {
-    return function mouseoverHandler() {
+    return () => {
       const rectListItem = union.listItem.getBoundingClientRect();
       const rectSubMenu = union.submenu.getBoundingClientRect();
 
@@ -71,7 +75,6 @@ export class Asidenav {
       } else {
         union.submenu.style.top = rectListItem.top + 'px';
       }
-
     };
   }
 }
diff --git a/frontend/src/utils/async-table/async-table.js b/frontend/src/utils/async-table/async-table.js
index d3da0b6f3..f32f8df33 100644
--- a/frontend/src/utils/async-table/async-table.js
+++ b/frontend/src/utils/async-table/async-table.js
@@ -1,5 +1,6 @@
 import { Utility } from '../../core/utility';
 import { HttpClient } from '../../services/http-client/http-client';
+import * as debounce from 'lodash.debounce';
 import './async-table-filter.scss';
 import './async-table.scss';
 
@@ -132,7 +133,6 @@ export class AsyncTable {
 
   _setupTableFilter() {
     const tableFilterForm = this._element.querySelector(ASYNC_TABLE_FILTER_FORM_SELECTOR);
-
     if (tableFilterForm) {
       this._gatherTableFilterInputs(tableFilterForm);
       this._addTableFilterEventListeners(tableFilterForm);
@@ -140,62 +140,62 @@ export class AsyncTable {
   }
 
   _gatherTableFilterInputs(tableFilterForm) {
-    Array.from(tableFilterForm.querySelectorAll('input[type="search"]')).forEach(function(input) {
+    Array.from(tableFilterForm.querySelectorAll('input[type="search"]')).forEach((input) => {
       this._tableFilterInputs.search.push(input);
     });
 
-    Array.from(tableFilterForm.querySelectorAll('input[type="text"]')).forEach(function(input) {
+    Array.from(tableFilterForm.querySelectorAll('input[type="text"]')).forEach((input) => {
       this._tableFilterInputs.input.push(input);
     });
 
-    Array.from(tableFilterForm.querySelectorAll('input:not([type="text"]):not([type="search"])')).forEach(function(input) {
+    Array.from(tableFilterForm.querySelectorAll('input:not([type="text"]):not([type="search"])')).forEach((input) => {
       this._tableFilterInputs.change.push(input);
     });
 
-    Array.from(tableFilterForm.querySelectorAll('select')).forEach(function(input) {
+    Array.from(tableFilterForm.querySelectorAll('select')).forEach((input) => {
       this._tableFilterInputs.select.push(input);
     });
   }
 
   _addTableFilterEventListeners(tableFilterForm) {
-    this._tableFilterInputs.search.forEach(function(input) {
-      const debouncedInput = debounce(function() {
+    this._tableFilterInputs.search.forEach((input) => {
+      const debouncedInput = debounce(() => {
         if (input.value.length === 0 || input.value.length > 2) {
-          this.updateFromTableFilter(tableFilterForm);
+          this._updateFromTableFilter(tableFilterForm);
         }
       }, INPUT_DEBOUNCE);
       input.addEventListener('input', debouncedInput);
     });
 
-    this._tableFilterInputs.input.forEach(function(input) {
-      const debouncedInput = debounce(function() {
+    this._tableFilterInputs.input.forEach((input) => {
+      const debouncedInput = debounce(() => {
         if (input.value.length === 0 || input.value.length > 2) {
-          this.updateFromTableFilter(tableFilterForm);
+          this._updateFromTableFilter(tableFilterForm);
         }
       }, INPUT_DEBOUNCE);
       input.addEventListener('input', debouncedInput);
     });
 
-    this._tableFilterInputs.change.forEach(function(input) {
-      input.addEventListener('change', function() {
-        this.updateFromTableFilter(tableFilterForm);
+    this._tableFilterInputs.change.forEach((input) => {
+      input.addEventListener('change', () => {
+        this._updateFromTableFilter(tableFilterForm);
       });
     });
 
-    this._tableFilterInputs.select.forEach(function(input) {
-      input.addEventListener('change', function() {
-        this.updateFromTableFilter(tableFilterForm);
+    this._tableFilterInputs.select.forEach((input) => {
+      input.addEventListener('change', () => {
+        this._updateFromTableFilter(tableFilterForm);
       });
     });
 
-    tableFilterForm.addEventListener('submit', function(event) {
+    tableFilterForm.addEventListener('submit', (event) =>{
       event.preventDefault();
-      this.updateFromTableFilter(tableFilterForm);
+      this._updateFromTableFilter(tableFilterForm);
     });
   }
 
   _updateFromTableFilter(tableFilterForm) {
-    const url = this.serializeTableFilterToURL();
+    const url = this._serializeTableFilterToURL();
     let callback = null;
 
     const focusedInput = tableFilterForm.querySelector(':focus, :active');
@@ -218,7 +218,7 @@ export class AsyncTable {
     this._updateTableFrom(url, callback);
   }
 
-  serializeTableFilterToURL() {
+  _serializeTableFilterToURL() {
     const url = new URL(getLocalStorageParameter('currentTableUrl') || window.location.href);
 
     const formIdElement = this._element.querySelector(ASYNC_TABLE_FILTER_FORM_ID_SELECTOR);
@@ -383,19 +383,3 @@ function getLocalStorageParameter(key) {
   const currentLSState = JSON.parse(window.localStorage.getItem(ASYNC_TABLE_LOCAL_STORAGE_KEY)) || {};
   return currentLSState[key];
 }
-
-// debounce function, taken from Underscore.js
-function debounce(func, wait, immediate) {
-  let timeout;
-  return function() {
-    const context = this, args = arguments;
-    const later = function() {
-      timeout = null;
-      if (!immediate) func.apply(context, args);
-    };
-    const callNow = immediate && !timeout;
-    clearTimeout(timeout);
-    timeout = setTimeout(later, wait);
-    if (callNow) func.apply(context, args);
-  };
-}
diff --git a/frontend/src/utils/check-all/check-all.js b/frontend/src/utils/check-all/check-all.js
index d5fa39719..5c1a754db 100644
--- a/frontend/src/utils/check-all/check-all.js
+++ b/frontend/src/utils/check-all/check-all.js
@@ -46,9 +46,9 @@ export class CheckAll {
   _gatherColumns() {
     const rows = Array.from(this._element.querySelectorAll('tr'));
     const cols = [];
-    rows.forEach(function(tr) {
+    rows.forEach((tr) => {
       const cells = Array.from(tr.querySelectorAll('td'));
-      cells.forEach(function(cell, cellIndex) {
+      cells.forEach((cell, cellIndex) => {
         if (!cols[cellIndex]) {
           cols[cellIndex] = [];
         }
@@ -60,8 +60,8 @@ export class CheckAll {
 
   _findCheckboxColumn(columns) {
     let checkboxColumnId = null;
-    columns.forEach(function(col, i) {
-      if (this.isCheckboxColumn(col)) {
+    columns.forEach((col, i) => {
+      if (this._isCheckboxColumn(col)) {
         checkboxColumnId = i;
       }
     });
@@ -70,7 +70,7 @@ export class CheckAll {
 
   _isCheckboxColumn(col) {
     let onlyCheckboxes = true;
-    col.forEach(function(cell) {
+    col.forEach((cell) => {
       if (onlyCheckboxes && !cell.querySelector(CHECKBOX_SELECTOR)) {
         onlyCheckboxes = false;
       }
@@ -104,23 +104,23 @@ export class CheckAll {
   }
 
   _setupCheckboxListeners() {
-    this._checkboxColumn.map(function(cell) {
+    this._checkboxColumn.map((cell) => {
         return cell.querySelector(CHECKBOX_SELECTOR);
       })
-      .forEach(function(checkbox) {
+      .forEach((checkbox) => {
         checkbox.addEventListener('input', this.updateCheckAllCheckboxState);
       });
   }
 
   _updateCheckAllCheckboxState() {
-    const allChecked = this._checkboxColumn.every(function(cell) {
+    const allChecked = this._checkboxColumn.every((cell) => {
       return cell.querySelector(CHECKBOX_SELECTOR).checked;
     });
     this._checkAllCheckbox.checked = allChecked;
   }
 
   _toggleAll(checked) {
-    this._checkboxColumn.forEach(function(cell) {
+    this._checkboxColumn.forEach((cell) => {
       cell.querySelector(CHECKBOX_SELECTOR).checked = checked;
     });
   }