# File lib/grape/validations/validators/default.rb, line 20
      def validate!(params)
        attrs = AttributesIterator.new(self, @scope, params)
        attrs.each do |resource_params, attr_name|
          if resource_params.is_a?(Hash) && resource_params[attr_name].nil?
            validate_param!(attr_name, resource_params)
          end
        end
      end