public static void addLibrary( Class libraryClass )
                                                     throws SoundSystemException
    {
        if( libraryClass == null )
            throw new SoundSystemException(
                                        "Parameter null in method 'addLibrary'",
                                        SoundSystemException.NULL_PARAMETER );
        if( !Library.class.isAssignableFrom( libraryClass ) )
            throw new SoundSystemException( "The specified class does not " +
                              "extend class 'Library' in method 'addLibrary'" );

        if( libraries == null )
            libraries = new LinkedList<Class>();

        if( !libraries.contains( libraryClass ) )
            libraries.add( libraryClass );
    }