my::base           # base class
my::extended_trunk # extends base
my::branch_A       # extends "extended_trunk"
my::branch_B       # Also extends "extended_trunk"

my::base->configure(options);           # Options change in all Classes
my::extended_trunk->configure(options); # Options only change in extended_trunk and both branches
my::branch_A->configure(options);       # Options only change in branch_A