# File lib/travis/client/session.rb, line 156
      def preload(list)
        list.group_by(&:class).each do |type, instances|
          next unless type.preloadable?
          ids = instances.map { |e| e.id unless e.complete? }.compact
          find_many(type, :ids => ids) if ids.any?
        end
        list
      end