def Serialize(self):
    if not self.serializer:
      raise FlagsError(self.name % "Serializer not present for flag %s")
    if self.value is None:
      return ''

    s = ''

    multi_value = self.value

    for self.value in multi_value:
      if s: s += ' '
      s += Flag.Serialize(self)

    self.value = multi_value

    return s
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/python-gflags/gflags.py/MultiFlag.Serialize/swapped operands of `%`