anchor.diff:  ----
   function deco1 = |fun| {
     return |args...| {
  -    print("deco1 + ")
  -    return fun: invokeWithArguments(args)
  +    return "deco1 + " + fun: invokeWithArguments(args)
     }
   }
   ----
  
positive.code: 
  `println(baz(1))` will print `deco2 + deco1 + baz: 1`
  
  
  Moreover, since decorator are just higher order functions, they can be closure
  on a first argument, i.e. parametrized decorators, as illustrated in the following listing:
  
  [source,golo]
  ----
  
negative.code: }
  ----
  
  TBD: more explanations
  
  
  ==== Generic context ====
  
  Decorators can be used to define a generic wrapper around a function. This
  functionality is provided by the `gololang.Decorators.withContext` standard
  decorator. This decorator take a context, such as the one returned by
  `gololang.Decorators.defaultContext` function.
  
  A context is an object with 4 defined methods:
  