base:=Dictionary(
"name", "Rocket Skates",
"price", 12.75,
"color", "yellow",);
update:=Dictionary(
"price", 15.25,
"color", "red",
"year", 1974,);
update.pump( new:=base.copy() );
new.pump(Void,fcn([(k,v)]){ println("%s\t%s".fmt(k,v)) });