wrap_block_extension

# File activerecord/lib/active_record/associations/builder/collection_association.rb, line 34
      def wrap_block_extension
        options[:extend] = Array.wrap(options[:extend])

        if block_extension
          silence_warnings do
            model.parent.const_set(extension_module_name, Module.new(&block_extension))
          end
          options[:extend].push("#{model.parent}::#{extension_module_name}".constantize)
        end
      end