    # File lib/chef/mixin/why_run.rb, line 166
              def failure_message(*args)
                case args.size
                when 1
                  @failure_message = args[0]
                when 2
                  @exception_type, @failure_message = args[0], args[1]
                else
                  raise ArgumentError, "#{self.class}#failure_message takes 1 or 2 arguments, you gave #{args.inspect}"
                end
              end