Singleton mimicry

gistfile1.as

package
{
  public function get SoundManager():ISoundManager
	{
		return _instance||= new SoundManagerImpl();
	}
}
 
import flash.media.Sound;
 
var _instance:SoundManagerImpl;
class SoundManagerImpl implements ISoundManager
{
	public function playSound(value:Sound):void
	{
		//...
	}
}
//...
SoundManager.playSound(mySound);
var soundManager:ISoundManager = SoundManager;// или getSoundManager();