code: def _oid(self, x):
          
          xl = x.strip(".").split(".")
          p = len(xl) - 1
          while p >= 0 and _mib_re_integer.match(xl[p]):
              p -= 1
          if p != 0 or xl[p] not in six.itervalues(self.__dict__):
              return x
          xl[p] = next(k for k, v in six.iteritems(self.__dict__) if v == xl[p])
          return ".".join(xl[p:])
docs: Parse the OID id/OID generator, and return real OID