boxcol 
    {box; box; box;}
boxcol [content.y=bottom]
    {box; box; box;}
boxcol [content.y=justify]
    {box; box; box;}
use line.color=blue;
space;
boxcol [height=140]
    {box; box; box;}
boxcol [content.y=bottom, height=140]
    {box; box; box;}
boxcol [content.y=justify, height=140]
    {box; box; box;}
