# File lib/rspec/core/formatters/base_formatter.rb, line 95
        def format_backtrace(backtrace, example)
          return "" unless backtrace
          return backtrace if example.metadata[:full_backtrace] == true
          cleansed = backtrace.map { |line| backtrace_line(line) }.compact
          cleansed.empty? ? backtrace : cleansed
        end