# File lib/html5/filters/validator.rb, line 592
  def check_lang_code(token, tag_name, attr_name, attr_value)
    return if !attr_value || attr_value == '' # blank is OK
    if not is_valid_lang_code(attr_value)
      yield( {:type => "ParseError",
           :data => "invalid-lang-code",
           :datavars => {"tagName" => tag_name,
                "attributeName" => attr_name,
                "attributeValue" => attr_value}})
    end
  end