def message_verifier(verifier_name)
      @message_verifiers[verifier_name] ||= begin
        secret = key_generator.generate_key(verifier_name.to_s)
        ActiveSupport::MessageVerifier.new(secret)
      end
    end
def message_verifier(verifier_name)
      @message_verifiers[verifier_name] ||= begin
        secret = key_generator.generate_key(verifier_name.to_s)
        ActiveSupport::MessageVerifier.new(secret)
      end
    end
Returns a message verifier object.

 This verifier can be used to generate and verify signed messages in the application.

 It is recommended not to use the same verifier for different things, so you can get different
 verifiers passing the +verifier_name+ argument.

 ==== Parameters

 * +verifier_name+ - the name of the message verifier.

 ==== Examples

     message = Rails.application.message_verifier('sensitive_data').generate('my sensible data')
     Rails.application.message_verifier('sensitive_data').verify(message)
     # => 'my sensible data'

 See the +ActiveSupport::MessageVerifier+ documentation for more information.