  This is the reply to [arXiv:1711.00764], in which the authors claim that
there is crucial normalization error in PRL 116, 040502 (2016) and that some
quantities appearing in the method of PRL 116, 040502 (2016) are not
experimentally measurable. We show that the claim of [arXiv:1711.00764] is not
correct and that the quantities appearing in PRL 116, 040502 (2016) can be
measured.
