docs: def validate(self, value):
          """
          Accepts: str, unicode
          Returns: list of tuples in the format (ip, port)
          """
          val = super(SlavesValue, self).validate(value)
  
          slaves = val.replace(" ", "")
          slaves = filter(None, slaves.split(','))
          slaves = [x.split(":") for x in slaves]
          res = list()
          for x in slaves:
              self._validate_ip(x[0])
              if len(x) == 1:
                  res.append((x[0], 53))
              else:
                  res.append((x[0], int(x[1])))
          return res