         tri
     ] { } make ;
 
-: class-usage ( class -- seq ) update-map get at keys ;
+: class-usage ( class -- seq )
+    update-map get at sets:members ;
 
 <PRIVATE
 

<PRIVATE

: update-map+ ( class -- )
    dup class-uses update-map get add-vertex ;

: update-map- ( class -- )
    dup class-uses update-map get remove-vertex ;

: implementors-map+ ( class -- )
    [ HS{ } clone ] dip implementors-map get set-at ;

USING: accessors assocs combinators definitions kernel
make namespaces quotations sequences sets words words.symbol ;
FROM: namespaces => set ;
QUALIFIED: sets
IN: classes

