Events last part video +5' not work for me

app/Http/Livewire/HelloWorld.php

@@ -7,8 +7,6 @@ use App\Models\Contact;
 
 class HelloWorld extends Component
 {
-    public $names = ['AbdelKarim', 'Chico', 'Man'];
-
     public $contacts;
 
     public function mount()
@@ -16,11 +14,6 @@ class HelloWorld extends Component
         $this->contacts = Contact::all();
     }
 
-    public function refreshChildren()
-    {
-        $this->emit('refreshChildren');
-    }
-
     public function render()
     {
         return view('livewire.hello-world');

app/Http/Livewire/SayHi.php

@@ -9,13 +9,6 @@ class SayHi extends Component
 {
     public $contact;
 
-    protected $listeners = ['refreshChildren' => 'refreshMe'];
-
-    public function refreshMe()
-    {
-
-    }
-
     public function mount(Contact $contact)
     {
         $this->contact = $contact;

resources/views/livewire/hello-world.blade.php

@@ -9,5 +9,5 @@
 
     {{ now() }}
 
-    <button wire:click="refreshChildren">Refresh children</button>
+    <button wire:click="$emit('refreshChildren)">Refresh children</button>
 </div>