... Scheming arXiv:astro-ph abstracts almost an year never offered me an occasion that the fit of the Poisson distribution is tested in different ways, instead it is taken for granted by plugging data and (source) model into a (modified) ? ... Abstract: goodness-of-fit tests based on the Cramer-von Mises statistics are given for the Poisson distribution. ... 2 statistic for testing the goodness of fit in astronomy and this D statistics is considered as a two sided test approximately distributed as a ? ...