def METHOD_NAME(self, x):
    if not (self.alpha > 0.0 and self.beta > 0.0):
        return float("-inf")
    log_pdf = -((x[0] / self.beta) ** self.alpha)
    log_pdf += (self.alpha - 1) * m.log(x[0] / self.beta) * x[1]
    log_pdf += m.log(self.alpha / self.beta) * x[1]
    return log_pdf