anchor.diff:  
   === Asynchronous Handlers
   
  -_Catacumba_ has support for multiple abstractions for asynchronous (stream or not) abstractions and
  -addopts a flexible and extensible way for make easy for the user adapt it to hes needs and hes
  -abstractions.
  -
  -The main abstraction are defined in the link:https://github.com/funcool/futura[futura library],
  -that provides basic building blocks for promise like abstractions and stream abstraction.
  -
  -The link:https://github.com/funcool/futura[futura library] instead of reinvent the wheel, is build
  -up on existing implementations such as:
  -
  -* _JDK8 CompletableFuture_ for *promise* abstraction.
  -* _Reactive Streams_ for the *stream* abstraction.
  -
  -Using the link:http://www.reactive-streams.org/[reactive streams] instead of reinvent yet another
  -stream abstraction has huge amount of advantages. There three most important:
  -
  -* Interoprability with all libraries that has support for reactive streams
  -* Well and strongly defined behavior of the abstraction.
  -* Comes with support for *backpressure* in its core (that is mandatory in asynchronous environments).
  +Asynchronous handlers are handlers that return a value in asyncrhonous way using one of the
  +supported abstractions, such as core.async, reactve-streams and much others (explained below).
   
   
   ==== Channels
  
positive.code: officially replaces this non-standard header.
  
  
  === Strict Transport Security
  
  This is a security related chain handler that adds the `Strict-Transport-Security` to the response.
  
  
negative.code: circumstances this is completely irelevant because it is done in a application bootstrap time.
  
  For understand it better, _catacumba_ comes with an <<sse-component-example,example>> that builds a
  multiuser char using "Server-Sent events" and component, so you can experiment with real code.
  See the <<examples,examples>> section for it.
  
  
  