Markup padding \override

[Bertalan Fodor]

I'm trying to set the padding property of a markup text. I thought \override
is the thing I need. So I tried:
\markup \override #'(padding . 1) { \box "B" }
But it doesn't work. Isn't \override for that?

So I had to stay with 
\once \property Voice.TextScript \override #'padding = #1
which works OK.

Greetings,
Bert