I want to draw a table with two `\hline` and two vertical line. But as shown in the figure, the first vertical line do not cross the two hline. How to solve this problem?

```
\documentclass{article}
\usepackage{hhline}
\begin{document}

\begin{tabular}{c||c||c}
\hline 
1 & 2 & 3 \\ \hhline{=|=|=}
4 & 5 & 6 \\ \hline
7 & 8 & 9 \\ \hline
\end{tabular}

\end{document}

```

![output](https://i.stack.imgur.com/Va0gO.png)