QwtDynGridLayout(3) on Linux
The text 9206ae62daea, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster) shipped it. The page shows this text now.
The QwtDynGridLayout class lays out widgets in a grid, adjusting the number of columns and rows to the current size.