Strict done!!

overlord/src/app/user/user-list/user-list.component.ts

@@ -15,8 +15,8 @@ import { UserListDataSource } from './user-list-datasource';
 export class UserListComponent implements OnInit {
   @ViewChild(MatPaginator, { static: true }) paginator?: MatPaginator = undefined;
   @ViewChild(MatSort, { static: true }) sort?: MatSort = undefined;
-  dataSource: UserListDataSource;
-  list: User[];
+  list: User[] = [];
+  dataSource: UserListDataSource = new UserListDataSource(this.list);
   /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
   displayedColumns = ['name', 'lockedOut', 'groups'];
 
@@ -27,6 +27,6 @@ export class UserListComponent implements OnInit {
       const data = value as { list: User[] };
       this.list = data.list;
     });
-    this.dataSource = new UserListDataSource(this.paginator, this.sort, this.list);
+    this.dataSource = new UserListDataSource(this.list, this.paginator, this.sort);
   }
 }