anchor.diff:  that acts on the handling context.
   
   Do not worry about the context, it will be explained in below sections. The only thing that you
  -shoult known about context at this time, that is the central part of the request and response
  +shoult known about it at this time, is that is the central part of the request and response
   lifetime. It stores the current state of the http request and everything related.
   
   The hello world handler has this aspect:
  
positive.code: 
  The order of statemens is very important because the routing in _catacumba_ is a simple chain or in
  other words: pipeline. The handlers has the ability to delegate the request handign to the next
  handler in the pipeline. If you know the *pedestal* interceptors concept, this is maybe also
  familiar for you.
  
  Additionally to `:get` route type that you have seen in previous example, it there others that already
  supported in _catacumba_'s routing: `:any` (matches all routes, often used for add chain handlers),
  `:post`, `:put`, `:patch` and `:delete`.
  
  
  ==== Dispatch by method
  
  In some circumstances you may want have different handlers depending on the http method used
  for one concrete endpoint. For it exists the `:method` route directive:
  
  [source, clojure]
  ----
  
negative.code:                [:get "users" users-handler]]]))
  ----
  
  For better understanding how the handlers chain delegation works, see the *Context* chapter.
  
  
  ==== Error handling
  
  The _catacumba_ router chain allows setup user defined error handling functions. Do it, is very
  simple, just add an other route entry with `:error` route directive:
  
  [source, clojure]
  ----
  