Used by our custom assertTag() and assertNotTag() assertions, that some
day we should deprecate... the loading of XML content for further
processing has been moved to new classes within the PHPUnit utils. We
are just following the move here.
- count() can only be called on arrays or Countable, it can not be called on null
- recordset is neither so iterator_count() should be used
- instanceof or get_class() can not be applied to non-objects
- class methods must have the same arguments as methods in parent class