private fun read_data(xml: XMLStartTag, tag_name: String): String do
var res = ""
if xml[tag_name].is_empty then return res
var first = xml[tag_name].first
if not first isa XMLStartTag then return res
var data = first.data
if data == null then return res
return data
end
lib/nlp/stanford.nit:290,2--298,4