don't destroy on load creates multiple objects in unity code example

Example: unity clone don't destroy on scene load

private static Player playerInstance; 

void Awake(){     
	 DontDestroyOnLoad (this);
	 
  if (playerInstance == null) {         
 	playerInstance = this;     
	 } 
  else {
 	DestroyObject(gameObject);
 	} 
 }