Final public method for abstract class

All public methods of abstract classes should be final. Enforce API encapsulation in an inheritance architecture. If you want to override a method, use the Template method pattern.

Behavioral/Mediator/Colleague.php

@@ -8,7 +8,7 @@ abstract class Colleague
 {
     protected Mediator $mediator;
 
-    public function setMediator(Mediator $mediator)
+    final public function setMediator(Mediator $mediator)
     {
         $this->mediator = $mediator;
     }

Behavioral/TemplateMethod/Journey.php

@@ -58,7 +58,7 @@ abstract class Journey
     /**
      * @return string[]
      */
-    public function getThingsToDo(): array
+    final public function getThingsToDo(): array
     {
         return $this->thingsToDo;
     }