onEithersG :: (r -> r') -> (l -> l') -> (forall f. Functor f => DSum (EitherG l r) f -> DSum (EitherG l' r') f)
onEithersG fr fl (RightG :=> x) = RightG :=> ( fr <$>  x)
onEithersG :: (r -> r') -> (l -> l') -> (forall f. Functor f => DSum (EitherG l r) f -> DSum (EitherG l' r') f)
onEithersG fr fl (RightG :=> x) = RightG :=> ( fr <$>  x)
onEithersG fr fl (RightG :=> x) = RightG :=> ( fr <$>  x)