anchor.diff:  
   The server uses an `Observable<HttpServerRequest>` to serve request:
   
  -link:src/main/java/io/vertx/example/rxjava/http/simple/Server.java[RxJava simple HTTP server]
  +link:src/main/java/io/vertx/example/rxjava/http/client/simple/Server.java[RxJava simple HTTP server]
   
   The client uses an `Observable<HttpClientRequest` and applies `flatMap` to get a `Observable<Buffer>`
   
  -link:src/main/java/io/vertx/example/rxjava/http/simple/Client.java[RxJava simple HTTP client]
  +link:src/main/java/io/vertx/example/rxjava/http/client/simple/Client.java[RxJava simple HTTP client]
   
   === Reduce
   
  
positive.code: 
  The main interest is to get the final result when the two responses are delivered.
  
  link:src/main/java/io/vertx/example/rxjava/http/zip/Client.java[RxJava zip HTTP client]
  
  === Unmarshalling
  
  The http client json response is unmarshalled to a Java object: the `RxHelper.unmarshaller` static method
   creates an Rx operator applied to the response via the `lift`.
  
  link:src/main/java/io/vertx/example/rxjava/http/unmarshalling/Client.java[RxJava unmarshalling HTTP client]
  
  == RxJava event bus examples
  
  
negative.code: * `map` transform the buffer to a string
  * `subscribe` delivers the response content
  
  link:src/main/java/io/vertx/example/rxjava/http/client/reduce/Client.java[RxJava reduce HTTP client]
  
  === Zip
  
  