def setUp(self):
    self._msg = array_ops.placeholder(dtype=dtypes.string)
    self._encoded_f = string_ops.encode_base64(self._msg, pad=False)
    self._decoded_f = string_ops.decode_base64(self._encoded_f)
    self._encoded_t = string_ops.encode_base64(self._msg, pad=True)
    self._decoded_t = string_ops.decode_base64(self._encoded_t)