Revert unwanted changes

Author: martinRenou

src/index.ts

@@ -2,6 +2,7 @@ import { ICommandPalette, WidgetTracker } from '@jupyterlab/apputils';
 
 import {
   ILabShell,
+  ILayoutRestorer,
   JupyterFrontEnd,
   JupyterFrontEndPlugin
 } from '@jupyterlab/application';
@@ -34,12 +35,13 @@ namespace CommandIDs {
  */
 const variableinspector: JupyterFrontEndPlugin<IVariableInspectorManager> = {
   id: '@lckr/jupyterlab_variableinspector',
-  requires: [ICommandPalette, ILabShell],
+  requires: [ICommandPalette, ILayoutRestorer, ILabShell],
   provides: IVariableInspectorManager,
   autoStart: true,
   activate: (
     app: JupyterFrontEnd,
     palette: ICommandPalette,
+    restorer: ILayoutRestorer,
     labShell: ILabShell
   ): IVariableInspectorManager => {
     const manager = new VariableInspectorManager();
@@ -71,6 +73,13 @@ const variableinspector: JupyterFrontEndPlugin<IVariableInspectorManager> = {
       return panel;
     }
 
+    // Enable state restoration
+    restorer.restore(tracker, {
+      command,
+      args: () => ({}),
+      name: () => 'variableinspector'
+    });
+
     // Add command to palette
     app.commands.addCommand(command, {
       label,