I would like to have some text vertically centered in a box.

I can get the text to be at the bottom of the box like this

```
\documentclass[]{standalone}

\usepackage{tikz}

\begin{document}
\begin{tikzpicture}
\fill[black, rounded corners=0.2cm] (0, 8) rectangle (8, 0)
            node[above left, white, text width=7.8cm, align=center] {Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.};
\end{tikzpicture}
\end{document}

```

But how do I get the text to be centered in the box?