class RSpec::Core::Formatters::JsonFormatter

def stop(notification)
  @output_hash[:examples] = notification.examples.map do |example|
    format_example(example).tap do |hash|
      e = example.exception
      if e
        hash[:exception] =  {
          :class => e.class.name,
          :message => e.message,
          :backtrace => e.backtrace,
        }
      end
    end
  end
end