def warn!(error, type)
      return unless logger
      message = "[Rack::Parser] Error on %s : %s" % [type, error.to_s]
      logger.warn message
    end
def warn!(error, type)
      return unless logger
      message = "[Rack::Parser] Error on %s : %s" % [type, error.to_s]
      logger.warn message
    end
Private: send a warning out to the logger

 error - Exception object
 type  - String of the Content-Type