class example_record 
	   does Compact 
	   is finalized
	   {
	   has Str $.name
	      is rw
		  should serialize (:length_prefix(2), :encoding(UTF16), 
							padding => {:char("\0", :strip} );
	   has int16 $.val is rw;
	   has Str $!presentation_cache;  # private, not included in compact struct I/O
	   method presentation () returns Str
	      {
		  unless defined $!presentation_cache {
		     ... # compute it
			 }
		  return $!presentation_cache;
		  }
	   }