** Implement to define a 'ResponseProcessor'.
**
** 'ResponseProcessors' are responsible for processing the return values from request handlers. Often this involves
** sending content to the client.
**
** Example 'ResponseProcessors' that are provided by BedSheet are:
** - 'RedirectProcessor' - sets the 'Location' HTTP response header and a corresponding HTTP status code.
** - 'TextProcessor' - sets the 'Content-Type' HTTP response header and sends the text to the client.
**
** IoC Configuration
** =================
** Instances of 'ResponseProcessor' should be contributed to the 'ResponseProcessors' service and mapped to an
** 'Type' representing the object it handles.
**
** For example, in your 'AppModule' class:
**
** pre>
** syntax: fantom
** @Contribute { serviceType=ResponseProcessors# }
** Void contributeResponseProcessors(Configuration config) {
** config[User#] = UserInfoPage()
** }
** <pre
const mixin ResponseProcessor {
** Return 'true' if a response has been sent to the client and all processing has finished.
** Else return a response object for further processing, example, `Text` or `HttpStatus`.
abstract Obj process(Obj response)
}
