Comment #1 on issue 577 by alexandr...(a)gmail.com: ChildrenShape does not
get centered
http://code.google.com/p/moose-technology/issues/detail?id=577
I think all the pieces are there. But I need more info about what: #pref,
#center and #fill do.
Can you give a short description for each of them? I will use your answer
to write new examples and class documentation. Are some of them
incompatible? Is #center and #fill not incompatible? If I want a component
to fill all the space, how can I want it to be in the center?