Global variable using ruby singleton pattern

sqs.rb

class SQSToken
  class << self
    def get_token
      puts @@sqs_token ||= magic_method_which_gets_the_token_the_first_time
    end

    # Replace this method with a call to what ever magic
    # code that gets a new token only if required
    def magic_method_which_gets_the_token_the_first_time
      puts 'ive run!'

      "magic string!"
    end
  end
end


SQSToken.get_token # 1st run it will set the token and set a class variable
SQSToken.get_token # 2nd run it will return the previously set variable

# ruby sqs.rb
# ive run!
# magic string!
# magic string!