def getInterval(self, alpha):
        """ Evaluate the interval corresponding to a C.L. of (1-alpha)%.

        Parameters
        ----------
        alpha : limit confidence level.
        """
        dlnl = twosided_cl_to_dlnl(1.0 - alpha)
        lo_lim = self.getDeltaLogLike(dlnl, upper=False)
        hi_lim = self.getDeltaLogLike(dlnl, upper=True)
        return (lo_lim, hi_lim)