Remove the unnecessary line because of optimization for the Track component.

dist/js/splide.esm.js

@@ -1,6 +1,6 @@
 /*!
  * Splide.js
- * Version  : 2.4.4
+ * Version  : 2.4.5
  * License  : MIT
  * Copyright: 2020 Naotoshi Fujita
  */
@@ -360,7 +360,6 @@ function merge(_ref, from) {
  */
 
 function object_assign(to, from) {
-  to._s = from;
   keys(from).forEach(function (key) {
     if (!to[key]) {
       Object.defineProperty(to, key, Object.getOwnPropertyDescriptor(from, key));

dist/js/splide.js

@@ -1,6 +1,6 @@
 /*!
  * Splide.js
- * Version  : 2.4.4
+ * Version  : 2.4.5
  * License  : MIT
  * Copyright: 2020 Naotoshi Fujita
  */
@@ -350,7 +350,6 @@ function merge(_ref, from) {
  */
 
 function object_assign(to, from) {
-  to._s = from;
   keys(from).forEach(function (key) {
     if (!to[key]) {
       Object.defineProperty(to, key, Object.getOwnPropertyDescriptor(from, key));

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@splidejs/splide",
-  "version": "2.4.4",
+  "version": "2.4.5",
   "description": "Splide is a lightweight and powerful slider without any dependencies.",
   "author": "Naotoshi Fujita",
   "license": "MIT",

src/js/utils/object.js

@@ -76,8 +76,6 @@ export function merge( { ...to }, from ) {
  * @return {Object} - An assigned object.
  */
 export function assign( to, from ) {
-	to._s = from;
-
 	keys( from ).forEach( key => {
 		if ( ! to[ key ] ) {
 			Object.defineProperty( to, key, Object.getOwnPropertyDescriptor( from, key ) );