[Dbix-class] Class::Accessor::Grouped - how to use it?

[q]

Hi,

it's probably an awful question, but I could not figure out the rationale 
behind the module Class::Accessor::Grouped. The concept of accessors I know 
of, but I do not understand what this "group" thing is all about. Does 
anybody know where I can find more information regarding this? Or maybe a 
short explanation?

thanks wolfgang