Use W3C XSD schema to validate the document as it is processed. Activation is only possible before the first Read().
The filename of the XSD schema.
Returns true on success or false on failure.
Exceptions and Errors
Issues E_WARNING if libxml was built without schema support, the schema contains errors or if XMLReader::read has already been called.
This function is only available when PHP is compiled against libxml 20620 or later.