def GetUserSharedBy(self, user_id):
    key = user_id
    if key not in self.us_sb_acc_dict:
      self.us_sb_acc_dict[key] = Accounting.CreateUserSharedBy(user_id)
    return self.us_sb_acc_dict[key]
Returns the user shared_by accounting for the given user.
dataset/ETHPy150Open viewfinderco/viewfinder/backend/db/accounting.py/AccountingAccumulator.GetUserSharedBy