value_nodes = p.xpathEval("//rule/argument[value!='']/value")
element_nodes = p.xpathEval("//argument[value!='']/parent::rule/@element")
value_nodes = p.xpathEval("//rule/argument[value!='']/value")
element_nodes = p.xpathEval("//argument[value!='']/parent::rule/@element")
if (len(element_nodes)>1):
raise Exception("Invalid rule %s contains multiple elements."%xmlextension_path)
if (len(element_nodes)>1):
raise Exception("Invalid rule %s contains multiple elements."%xmlextension_path)