code: func NewInfiniteLoopWithIntro(src ReadSeekCloser, introLength int64, loopLength int64) *InfiniteLoop {
  	return &InfiniteLoop{
  		src:     src,
  		lstart:  introLength,
  		llength: loopLength,
  		pos:     -1,
  	}
  }
docs: // NewInfiniteLoopWithIntro creates a new infinite loop stream with an intro part.
  // NewInfiniteLoopWithIntro accepts a source stream src, introLength in bytes and loopLength in bytes.