docs: def remove_this_opinion(self,opinion_id):
          """
          Removes the opinion for the given opinion identifier
          @type opinion_id: string
          @param opinion_id: the opinion identifier to be removed
          """
          for opi in self.get_opinions():
              if opi.get_id() == opinion_id:
                  self.node.remove(opi.get_node())
                  break