Help me solve the problem in linux

below are the command and the error show when compile…

class MyLogger
private_class_method :new
@@logger = nil
def MyLogger.create
@@logger = new unless @@logger
@@logger
end
end

the error shows as follow:

1.rb:9: warning: Object#id will be deprecated; use Object#object_id

thanx for your help
and i would like to know about singletons.