anchor.diff:  
   For example `--spring.cloud.stream.poller.fixed-delay=2000` sets the poller interval to poll every two seconds.
   
  -===== Foreign event-driven sources
  +===== Sending arbitrary data to an output (e.g. Foreign event-driven sources)
   
   There are cases where the actual source of data may be coming from the external (foreign) system that is not a binder. For example, the
   source of the data may be a classic REST endpoint. How do we bridge such source with the functional mechanism used by spring-cloud-stream?
  
positive.code: 
  ====== Using reactor API
  
  [source, java]
  ----
  @SpringBootApplication
  
negative.code: 
  	@Bean
  	public Supplier<Flux<String>> supplier() {
  		return () -> this.processor;
  	}
  }
  ----
  
  Same as before we declare a `Supplier` bean which returns `Flux<String>`. But given that this is a REST endpoint
  we send messages by simply posting to this REST endpoint.
  
  ----
  curl -H "Content-Type: text/plain" -X POST -d "hello from the other side" http://localhost:8080/
  ----
  
  By showing two example we want to emphasize the approach will work with any type of foreign sources.
  
  ===== Reactive Functions support
  
  