anchor.diff:          checkNonNull "map2" map2
   
           map1.Difference map2
  -
  +*)
       /// Returns a new map made from the given bindings.
       [<CompiledName("OfSeq")>]
       let inline ofSeq source : HashMap<'Key, 'T> =
  
positive.code: 
          /// <inherit />
          member __.TryGetValue (key, value) =
              match PatriciaHashMap.TryFind (uint32 key, trie) with
              | None ->
                  false
              | Some v ->
  
negative.code:         checkNonNull "map" map
  
          map.ToMap ()
  *)
      /// Searches the map looking for the first element where the given function
      /// returns a Some value. If no such element is found, returns None.
      [<CompiledName("TryPick")>]
  