# File lib/rspec/core/formatters/helpers.rb, line 6
      def format_backtrace(backtrace, options = {})
        return "" unless backtrace
        return backtrace if options[:full_backtrace] == true

        if at_exit_index = backtrace.index(RSpec::Core::Runner::AT_EXIT_HOOK_BACKTRACE_LINE)
          backtrace = backtrace[0, at_exit_index]
        end

        cleansed = backtrace.map { |line| backtrace_line(line) }.compact
        cleansed.empty? ? backtrace : cleansed
      end