code: def remove_condition(self, rank):
          
          self.conditions[:] = [r for r in self.conditions
              if r.get('rank') != rank]
docs: Remove a condition element using it's rank. You can find the
          rank and element for a match condition by iterating the match
          condition::
          
              >>> rule1 = rm.route_map_rules.get(0)
              >>> for condition in rule1.match_condition:
              ...   condition
              ... 
              Condition(rank=1, element=ExternalBGPPeer(name=bgppeer))
              Condition(rank=2, element=IPAccessList(name=myacl))
              Condition(rank=3, element=Metric(value=20))
          
          Then delete by rank. Call update on the rule after making the
          modification.
          
          :param int rank: rank of the condition to remove
          :raises UpdateElementFailed: failed to update rule
          :return: None