code: def teardown(self):
          
          pA, pB = self.endpoints
          if pA in pB.links:
              pB.links.remove(pA)
          if pB in pA.links:
              pA.links.remove(pB)
          return self
docs: Teardown the link.
          Removes endpoints from properties I{links} collection.
          @return: self
          @rtype: L{Link}