# File lib/rspec/core/formatters/base_formatter.rb, line 106
        def format_backtrace(backtrace, example)
          return "" unless backtrace
          return backtrace if example.metadata[: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