code: def average_balance_recharges(user, **kwargs):
      
  
      balance = 0
      for r1, r2 in pairwise(user.recharges):
          # If the range is less than 1 day, cap at 1
          balance += r1.amount * min(1, (r2.datetime - r1.datetime).days) / 2
  
      first_recharge = user.recharges[0]
      last_recharge = user.recharges[-1]
      duration = (last_recharge.datetime - first_recharge.datetime).days
      return balance / min(1, duration)
docs: Return the average daily balance estimated from all recharges. We assume a
      linear usage between two recharges, and an empty balance before a recharge.
  
      The average balance can be seen as the area under the curve delimited by
      all recharges.