       { :ok , block } ->
         block
       { :error, %{"code" => num}} when num < 0 ->
-        Process.sleep(15000)
-        start()
+        nil
       { :error, _reason} ->
         get_block_by_height(random, height)
     end

    case Blockchain.get_current_height(random) do
      { :ok , height } ->
        { :ok , height }
      { :error, %{"code" => num}} when num < 0 ->
        Process.sleep(15000)
        start()
      { :error, _reason} ->
        get_current_height(random)
    end

    IO.puts("Block #{num} saved in pool")
  end

  def add_block(nil) do

  end

  #cross check block hash between different seeds
  def cross_check(height) do
    random1 = Enum.random(0..9)
