anchor.diff:  === Backpressure-aware consimption
   
   The streams created using the `generate` function, are backpressure-aware
  -streams and can be consumed in backpressure-aware way. For this you need to pass
  -object that implements the `ISubscriber` protocol. Let see an example:
  +streams and can be consumed in an backpressure-aware way. For this you need to pass
  +an object, that implements the `ISubscriber` protocol. Lets see an example:
   
   [source, clojure]
   ----
  
positive.code:                (constantly 0)))
  ----
  
  The difference with the `create` function, the `generate` executes the
  factory function multiple and you need to call sink *once* for each
  execution. Additionally, you can maintain state between executions
  retuning the desired value, that value will passed as first argument
  on the next execution. You can provide an initial state using the
  second argument and dispose callback as third argument.
  
  Many simple observables can be converted to be backpressure-aware using
  the `to-flowable` function. Take cara that there are no magic, the buffering
  strategy is used by default for handle backpressure (over production).
  
  [source, clojure]
  ----
  
negative.code: ;; ==> on-end
  ----
  
  
  == Subject
  
  