anchor.diff:  ----
   (require '[promesa.exec :as exec])
   
  -@(p/promise (fn [resolve reject] (resolve 1)) exec/default-executor)
  +@(p/create (fn [resolve reject] (resolve 1)) exec/default-executor)
   ;; => 1
   ----
   
  
positive.code: ;; => #<Promise [~]>
  ----
  
  Another option is to create an empty promise using the `deferred` function
  and provide the value asynchronously using `p/resolve!` and `p/reject!`:
  
  
negative.code: [source, clojure]
  ----
  @(-> (p/delay 100 1)
       (p/then' inc)
       (p/then' inc))
  ;; => 3
  ----
  
  