Finds the first closest previous sibling of the node which
          is an element node. Note the handling of entities
          references is different than in the W3C DOM element
          traversal spec since we don't have back reference from
           entities content to entities references.

def previousElementSibling(self):
        """Finds the first closest previous sibling of the node which
          is an element node. Note the handling of entities
          references is different than in the W3C DOM element
          traversal spec since we don't have back reference from
           entities content to entities references. """
        ret = libxml2mod.xmlPreviousElementSibling(self._o)
        if ret is None:return None
        __tmp = xmlNode(_obj=ret)
        return __tmp