Create an XML Schemas validation context based on the given
           schema.

def schemaNewValidCtxt(self):
        """Create an XML Schemas validation context based on the given
           schema. """
        ret = libxml2mod.xmlSchemaNewValidCtxt(self._o)
        if ret is None:raise treeError('xmlSchemaNewValidCtxt() failed')
        __tmp = SchemaValidCtxt(_obj=ret)
        __tmp.schema = self
        return __tmp