a.swift

let cache = SpecializedCache<JSON>(name: "JSONCache")

// Dictionary
cache.async.addObject(JSON.dictionary(["key": "value"]), forKey: "dictionary")
cache.async.object(forKey: "dictionary") { json in
  print(json?.object)
}

// Array
cache.async.addObject(JSON.array([["key1": "value1"]]), forKey: "array")
cache.object("array") { json in
  print(json?.object)
}