     end
 
     def message(%{version: version}) do
-      "invalid version: #{inspect version}"
+      "invalid version: #{inspect(version)}"
     end
   end
 

          else
            convert_parts_to_integer(rest, [integer | acc])
          end
        :error ->
          convert_parts_to_integer(rest, [part | acc])
      end

    end

    defp require_digits(nil), do: :error

    defp require_digits(string) do
      if leading_zero?(string), do: :error, else: parse_digits(string, "")
    end
