Added class initialization to the default constructor
Added UNDEFINED to AudioVisualType enum
Initialized local variables from Default constructor
Added @override public String displayInfo()
Added ImageIcon displayCover(URI file)
Added Clip getSoundClip(URL fileURL)
Added overloaded method playSoundClip(URL fileURL)
Added overloaded method playSoundClip(final URL fileURL, long seconds)
Formatting
Added tests to be used in DEBUG mode
Added sound file