/**
  * Set the default field-types that should be translated. 
  * Must be an array of valid field types. These types only come into effect when the
  * fields that should be translatet *aren't* explicitly defined.
  * 
  * @example
  * <code>
  * // create translations for all fields of type "Varchar" and "HTMLText".
  * TranslatableDataObject::set_default_fieldtypes(array('Varchar', 'HTMLText'));
  * </code>
  * 
  * Defaults to: array('Varchar', 'Text', 'HTMLText')
  * 
  * @param array $types the field-types that should be translated if not explicitly set
  */
 public static function set_default_fieldtypes($types)
 {
     if (is_array($types)) {
         self::$default_field_types = $types;
     }
 }