def merge_super_states(group_name)
      super_states.inject(Set.new) do |set, state|
        set.merge state.tracked(group_name)
      end
    end
def merge_super_states(group_name)
      super_states.inject(Set.new) do |set, state|
        set.merge state.tracked(group_name)
      end
    end
call-seq:
   merge_super_states(group_name) => set

 Returns a set containing all the methods being tracked for +group_name+
 by the #super_states.