def _qname(self) -> Optional[QualName]:
        """Parse XML QName."""
        if self.test_string("*"):
            self.skip_ws()
            return False
        ident = self.yang_identifier()
        ws = self.skip_ws()
        try:
            next = self.peek()
        except EndOfInput:
            return ident, None
        if next == "(":
            return self._node_type(ident)
        if not ws and self.test_string(":"):
            res = (
                self.yang_identifier(),
                self.sctx.schema_data.prefix2ns(ident, self.sctx.text_mid))
        else:
            res = (ident, None)
        self.skip_ws()
        return res
Parse XML QName.