def clean_semver(cls, version_spec):
        return re.sub(r"([<>=~])\s+?v?", "\\1", version_spec, re.IGNORECASE)
def __update_covariance(self, means, rc, mc):
        covariance = 0.0
        for index_point in range(len(self.__data)):
            deviation = numpy.array([self.__data[index_point] - means])
            covariance += rc[index_point] * deviation.T.dot(deviation)