setup_fixtures

# File activerecord/lib/active_record/fixtures.rb, line 916
      def setup_fixtures
        return unless defined?(ActiveRecord) && !ActiveRecord::Base.configurations.blank?

        if pre_loaded_fixtures && !use_transactional_fixtures
          raise RuntimeError, 'pre_loaded_fixtures requires use_transactional_fixtures'
        end

        @fixture_cache = {}

        # Load fixtures once and begin transaction.
        if use_transactional_fixtures?
          if @@already_loaded_fixtures[self.class]
            @loaded_fixtures = @@already_loaded_fixtures[self.class]
          else
            load_fixtures
            @@already_loaded_fixtures[self.class] = @loaded_fixtures
          end
          ActiveRecord::Base.connection.increment_open_transactions
          ActiveRecord::Base.connection.begin_db_transaction
        # Load fixtures for every test.
        else
          Fixtures.reset_cache
          @@already_loaded_fixtures[self.class] = nil
          load_fixtures
        end

        # Instantiate fixtures for every test if requested.
        instantiate_fixtures if use_instantiated_fixtures
      end