def FnNot(value)
      if value.is_a?(Array)
        Fn.new('Not', value)
      else
        Fn.new('Not', [value])
      end
    end
def FnNot(value)
      if value.is_a?(Array)
        Fn.new('Not', value)
      else
        Fn.new('Not', [value])
      end
    end
Equivalent to the Cloudformation template built in function Fn::Not