# File lib/declarative_authorization/development_support/development_support.rb, line 101
        def descendants (role_symbol = nil)
          role_symbol ||= @role
          (@engine.rev_role_hierarchy[role_symbol] || []).
              collect {|higher_role| descendants(higher_role) }.flatten +
            (role_symbol == @role ? [] : [Role.for_sym(role_symbol, @engine)])
        end