anchor.diff:      let braRes = bra.Fold (fun acc elem -> acc + elem) 0
       Assert.AreEqual(braRes, aRes) 
   
  -let createRandBra count =
  -    let rand = System.Random()
  -    BlockResizeArray.Init count (fun i -> rand.Next())
  -
   type ArbitraryModifiers =    
       static member BlockResizeArray() = 
           Arb.generate<int> 
           |> Gen.suchThat (fun i -> i >= 0)
  -        |> Gen.map (fun i -> createRandBra (i * 10000))
  +        |> Gen.map (fun i -> BlockResizeArray.Init  (i * 10000) (fun i -> rand.Next()))
           |> Arb.fromGen
   
   [<SetUp>]
  
positive.code:         let b = bra.Filter f
          let a = Array.filter f arr
          compareByElems b a        
      Check.QuickThrowOnFailure <| testFun (fun e -> e % 3 = 2)
      
  [<Test>]
  let ``Random TryFind``() =   
  
negative.code: let testIters = 10
  let x = 1000UL
  let testLen = 1000000
  let rand = System.Random()
  
  let compareByElems (bra : BlockResizeArray<'T>) (arr : 'T []) = 
      let mutable res = true 
  