OptionalcustomAn array of custom environment variable names.
OptionalcustomAn array of custom header keys.
OptionaldataA function that formats the data before logging.
OptionalgenA function that generates an ID.
OptionalloggerAn instance of a logger.
OptionalonCallback function that will be called when the request is finished.
OptionalstdoutSpecifies whether the standard output is disabled.
Represents the options for the middleware.