_run_class_setup

# File activesupport/lib/active_support/testing/isolation.rb, line 20
      def _run_class_setup      # class setup method should only happen in parent
        @@class_setup_mutex.synchronize do
          unless defined?(@@ran_class_setup) || ENV['ISOLATION_TEST']
            self.class.setup if self.class.respond_to?(:setup)
            @@ran_class_setup = true
          end
        end
      end