# File lib/test/unit/collector.rb, line 25
      def add_test_cases(suite, test_cases)
        children_map = {}
        test_cases.each do |test_case|
          ancestor_classes = test_case.ancestors.find_all do |ancestor|
            ancestor.is_a?(Class)
          end
          parent = ancestor_classes[1]
          children_map[parent] ||= []
          children_map[parent] << test_case
        end

        root_test_cases = children_map.keys - test_cases
        root_test_cases.each do |root_test_case|
          add_test_case(suite, root_test_case, children_map)
        end
      end