 
     test "adds an error to the existing span", %{span: span} do
       until(fn ->
-        assert {:ok, [{^span, :error, %RuntimeError{message: "Exception"}, _stack}]} =
+        assert {:ok, [{^span, :error, %RuntimeError{message: "Exception"}, _stack} | _]} =
                  Test.Span.get(:add_error)
       end)
     end

      end)
    end

    test "adds an error to the created span" do
      until(fn ->
        assert {:ok, [{%Span{}, :error, %RuntimeError{message: "Exception"}, stack}]} =
                 Test.Span.get(:add_error)

        assert is_list(stack)

      end)
    end

    test "adds an error to the created span", %{pid: pid} do
      until(fn ->
        assert {:ok,
                [{%Span{pid: ^pid}, :error, %ArgumentError{message: "argument error"}, stack} | _]} =
                 Test.Span.get(:add_error)

        assert is_list(stack)
