def __dir__(self):
        return [node.tagName for node 
                in self._element.childNodes
                if node.nodeType != node.TEXT_NODE]
Woodbury vector in the gaussian likelihood case only is defined as
dataset/ETHPy150Open uwdata/termite-visualizations/web2py/gluon/contrib/pysimplesoap/simplexml.py/SimpleXMLElement.__dir__--crossover with--dataset/ETHPy150Open SheffieldML/GPy/GPy/inference/latent_function_inference/posterior.py/Posterior.woodbury_vector