Small refactor to add intention revealing message

Author: alindeman

lib/rspec/core/example_group.rb

@@ -242,7 +242,7 @@ def self.subclass(parent, args, &example_group_block)
         # 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.
-        subclass.send(:include, MemoizedHelpers.module_for(subclass))
+        MemoizedHelpers.define_helpers_on(subclass)
 
         subclass
       end

lib/rspec/core/memoized_helpers.rb

@@ -474,6 +474,11 @@ def self.module_for(example_group)
         end
       end
 
+      # @api private
+      def self.define_helpers_on(example_group)
+        example_group.send(:include, module_for(example_group))
+      end
+
       if Module.method(:const_defined?).arity == 1 # for 1.8
         # @api private
         #