class ActionDispatch::RequestEncoder

def initialize(mime_name, param_encoder, response_parser)
  @mime = Mime[mime_name]
  unless @mime
    raise ArgumentError, "Can't register a request encoder for " \
      "unregistered MIME Type: #{mime_name}. See `Mime::Type.register`."
  end
  @response_parser = response_parser || -> body { body }
  @param_encoder   = param_encoder   || :"to_#{@mime.symbol}".to_proc
end