# File lib/rspec/core/example_group.rb, line 245
      def self.subclass(parent, args, &example_group_block)
        subclass = Class.new(parent)
        subclass.set_it_up(*args)
        subclass.module_eval(&example_group_block) if example_group_block

        # The LetDefinitions module must be included _after_ other modules
        # to ensure that it takes precendence when there are name collisions.
        # Thus, we delay including it until after the example group block
        # has been eval'd.
        MemoizedHelpers.define_helpers_on(subclass)

        subclass
      end