code: def logwealthmix(self, *, mu, s, thres, memo):
      from math import sqrt
      import numpy as np
      from scipy.special import logsumexp
  
      sqrttp1 = sqrt(self.t + 1)
      y = s / sqrttp1 - (self.t / sqrttp1) * mu
  
      logEs = np.array(
          [
              self.__get_lam_sqrttp1(j) * y - v
              for j, v in sorted(memo.items())
          ]
      )
      logws = np.array(
          [self.get_log_weight(j) for j, _ in sorted(memo.items())]
      )
      j = len(logEs)
  
      while True:
          lowerbound = logsumexp(a=logEs + logws)
  
          if lowerbound >= thres:
              return lowerbound
  
          # quasiconcave after the maximum, otherwise lower bound variance with 0
          logupperexp = (
              logEs[-1]
              if logEs[-1] < max(logEs[:-1])
              else self.__get_lam_sqrttp1(j) * y
          )
          upperbound = logsumexp(
              a=[
                  lowerbound,
                  self.get_log_remaining_weight(j) + logupperexp,
              ]
          )
  
          if upperbound < thres:
              return upperbound
  
          v = self.__getVimpl(memo, j)
          logEs = np.append(logEs, self.__get_lam_sqrttp1(j) * y - v)
          logws = np.append(logws, self.get_log_weight(j))
          j += 1
  
label_desc: Use image node_id 7 for calling the CountableDiscreteBase obj's underlying member method code with example usage: obj.logwealthmix() and returns: lowerbound, upperbound