def multiple?(method_name)
      return false if association(method_name).nil?

      name = association(method_name).respond_to?(:many?) ? :many? : :collection?
      association(method_name).send(name)
    end
def multiple?(method_name)
      return false if association(method_name).nil?

      name = association(method_name).respond_to?(:many?) ? :many? : :collection?
      association(method_name).send(name)
    end
many? for Mongoid and collection? for AR