code: def rotation=(rot)
        if rot.to_s.downcase == 'stacked'
          @rotation_stacked = true
          @rotation = 0
        elsif rot.kind_of?(Integer)
          @rotation_stacked = false
          @rotation = rot % 360
        else
          raise TypeError, "rotation value must be an Integer or the String 'stacked'"
        end
      end
docs: Set the Text rotation
   Valid values: Integers from -90 to 90,
   or :stacked (sets #rotation_stacked to true)