code: public SequenceView<C> get(int index) {
  		int start = toStartIndex(index);
  		int end  = index + (getWindowSize() - 1);
  		return getBackingSequence().getSubSequence(start, end);
  	}
docs: Returns the window specified at the given index in offsets i.e. asking
  for position 2 in a moving window sequence of size 3 will get you
  the window starting at position 4.