code: def rob_helper(self, nums, low, high):
      prevMax = currMax = 0
      for index in range(low, high + 1):
          temp = currMax
          currMax = max(prevMax + nums[index], currMax)
          prevMax = temp
      return currMax
  
label_desc: Use image node_id 2 for calling the Solution obj's underlying member method code with example usage: obj.rob_helper(nums, low, high) and returns: currMax