missing errors_for method for formBuilder

errors_for.rb

module ActionView
  module Helpers
    class FormBuilder
      include ActionView::Helpers::TagHelper
      include ActionView::Context

      def errors_for(object_name, options = {})
        return if (errors = object.errors[object_name]).empty?

        options[:class] ||= 'form_input-errors' # default class

        limit = options[:limit].to_i

        errors = errors.first(limit) if limit > 0
        errors.map! { |e| content_tag(:li, e) }

        content_tag(:ul, errors.join.html_safe, options).html_safe
      end
    end
  end
end