docs: def get_span_ids(self):
          """
          Returns the span object of the term
          @rtype: List
          @return: the term span as list of wf ids
          """
          node_span = self.node.find('span')
          if node_span is not None:
              mySpan = Cspan(node_span)
              span_ids = mySpan.get_span_ids()
              return span_ids
          else:
              return []