class VLI<2.0.1 cpan:DLUGOSZ> 
	   does Compact::helper
	   {
	   # implements packing/unpacking as described in <http://www.dlugosz.com/ZIP2/VLI.html>
	   multi pack (Int value, *%adverbs) returns Buf
		{
		... respects standard signed/unsigned option,
		   supports unique options for encoding variations
		}
	   } # end class VLI

	class C does Compact is rw
		{
		has int32 $x;
		has Int $y is VLI;
		}