# File lib/rspec/core/metadata.rb, line 121
        def container_stack
          @container_stack ||= begin
                                 groups = [group = self]
                                 while group.has_key?(:example_group)
                                   groups << group[:example_group]
                                   group = group[:example_group]
                                 end
                                 groups
                               end
        end