add_example_group

# File lib/spec/runner/formatter/nested_text_formatter.rb, line 13
        def add_example_group(example_group)
          super

          current_nested_example_groups = described_example_group_chain
          current_nested_example_groups.each_with_index do |nested_example_group, i|
            unless nested_example_group == previous_nested_example_groups[i]
              output.puts "#{'  ' * i}#{nested_example_group.description_args.join}"
            end
          end

          @previous_nested_example_groups = described_example_group_chain
        end