anchor.diff:  handlers out of the box and allows to be extended with used defined ones.
   
   
  -=== Write to response
  +==== Write to response
   
   As you can observe from the previous example, no status code is provided, only the content. For
   send a complete response you can use a builtin response type or ring like hashmap:
  
positive.code: * Comes with support for *backpressure* in its core (that is mandatory in asynchronous environments).
  
  
  === Channels
  
  The `core.async` channels is one of the supported abstractions that comes with _catacumba_ out
  of the box. It consist in a handler that returns a body as a channel or response as a channel.
  
negative.code: of this documentation.
  
  
  ==== Error handling
  
  The _catacumba_ router chain allows setup user defined error handling functions. Do it is very
  simple, just add an other route entry of `:error` type:
  