@property
    def val_xml(self):
        return self._val_tmpl.format(
            wksht_ref=self._values_ref, val_count=len(self),
            val_pt_xml=self._val_pt_xml, nsdecls=''
        )
Lookup an existing SimpleDB domain. This differs from 
dataset/ETHPy150Open scanny/python-pptx/pptx/chart/data.py/_SeriesData.val_xml--crossover with--dataset/ETHPy150Open darcyliu/storyboard/boto/sdb/connection.py/SDBConnection.lookup