Working on step 4 of Fizz Buzz here. But whenever I modify the output of the fizzbuzzer method with the as_text method I get an undefined error

gistfile1.txt

class FizzBuzz

  	def as_text (input)
		input.to_string
	end

	def fizzbuzzer (limit)
		(1..limit).map do |n|
			if n % 15 == 0
				"fizzbuzz"
			elsif n % 5 == 0
				"buzz"
			elsif n % 3 == 0
				"fizz"
			else
				n
			end
		end
	end


end