code: def _reset_corpus_iterator(self):
          
          self.__context = etree.iterparse(self.urml_file, events=('end',),
                                           tag='document', recover=False)
docs: create an iterator over all documents in the file (i.e. all
          <text> elements).
  
          Once you have iterated over all documents, call this method again
          if you want to iterate over them again.