def backtrace_to_s
      trace = ''
      each_exception do |exception, i|
        if i.zero?
          trace = (exception.backtrace || []).join("\n")
        else
          trace << "\nCause: #{exception.class.name}: #{exception.message}\n#{(exception.backtrace || []).join("\n")}"
        end
      end
      trace
    end
def backtrace_to_s
      trace = ''
      each_exception do |exception, i|
        if i.zero?
          trace = (exception.backtrace || []).join("\n")
        else
          trace << "\nCause: #{exception.class.name}: #{exception.message}\n#{(exception.backtrace || []).join("\n")}"
        end
      end
      trace
    end
Returns [String] the exception backtrace including all of the child / caused by exceptions