code: static void addCap(RingBuffer.Sequence sequence, long toAdd) {
  		long u, r;
  		do {
  			r = sequence.getAsLong();
  			if (r == Long.MAX_VALUE) {
  				return;
  			}
  			u = Operators.addCap(r, toAdd);
  		}
  		while (!sequence.compareAndSet(r, u));
  	}
docs: Concurrent addition bound to Long.MAX_VALUE. Any concurrent write will "happen"
  before this operation.
  
  @param sequence current sequence to update
  @param toAdd delta to add