what is the right way to release memory for a display object? using director

[lua]myGroup = display.newGroup()
– other code
– add objects to newGroup
– object = display.new(xxx)

myGroup:insert(object)

– about to leave screen, call cleanup()

cleanup = function()
myGroup:remove(object)
object = nil

– is this really required?
myGroup:removeSelf()
myGroup = nil
end[/lua]

is there any step which i may be missing to cleanup? (eg calling destroy on the object?)
[import]uid: 55009 topic_id: 12662 reply_id: 312662[/import]