old_contents: """
      Instabot Checkpoint methods.
  """
  
  import os
  import pickle
  from datetime import datetime
  
  CHECKPOINT_PATH = "instabot.checkpoint"
  
  class Checkpoint(object):
      """
          Checkpoint for instabot.Bot which can store:
              .total_<name> - all Bot's counters
              .following (list of user_ids)
              .followers (list of user_ids)
              .date (of checkpoint creation)
      """
  
      def __init__(self, bot):
          self.total_liked = bot.total_liked
          self.total_unliked = bot.total_unliked
          self.total_followed = bot.total_followed
          self.total_unfollowed = bot.total_unfollowed
          self.total_commented = bot.total_commented
          self.total_blocked = bot.total_blocked
          self.total_unblocked = bot.total_unblocked
          self.start_time = bot.start_time
          self.date = datetime.now()
  
  
      def fill_following(self, bot):
          self.following = [item["pk"] for item in bot.getTotalSelfFollowings()]
  
  
      def fill_followers(self, bot):
          self.followers = [item["pk"] for item in bot.getTotalSelfFollowers()]
  
  
      def dump(self):
          return (self.total_liked, self.total_unliked, self.total_followed,
                  self.total_unfollowed, self.total_commented,
                  self.total_blocked, self.total_unblocked, self.start_time)
  
  
  def save_checkpoint(self):
      cp = Checkpoint(self)
  
      with open(CHECKPOINT_PATH, 'wb') as f:
          pickle.dump(cp, f, -1)
      return True
  
  
  def load_checkpoint(self):
      try:
          with open(CHECKPOINT_PATH, 'rb') as f:
              cp = pickle.load(f)
          if isinstance(cp, Checkpoint):
              return cp.dump()
          else:
              os.remove(CHECKPOINT_PATH)
      except:
          pass
      return None
  
new_contents: """
      Instabot Checkpoint methods.
  """
  
  import os
  import pickle
  from datetime import datetime
  
  CHECKPOINT_PATH = "instabot.checkpoint"
  
  class Checkpoint(object):
      """
          Checkpoint for instabot.Bot class which can store:
              .total_<name> - all Bot's counters
              .following (list of user_ids)
              .followers (list of user_ids)
              .date (of checkpoint creation)
      """
  
      def __init__(self, bot):
          self.total_liked = bot.total_liked
          self.total_unliked = bot.total_unliked
          self.total_followed = bot.total_followed
          self.total_unfollowed = bot.total_unfollowed
          self.total_commented = bot.total_commented
          self.total_blocked = bot.total_blocked
          self.total_unblocked = bot.total_unblocked
          self.start_time = bot.start_time
          self.date = datetime.now()
  
  
      def fill_following(self, bot):
          self.following = [item["pk"] for item in bot.getTotalSelfFollowings()]
  
  
      def fill_followers(self, bot):
          self.followers = [item["pk"] for item in bot.getTotalSelfFollowers()]
  
  
      def dump(self):
          return (self.total_liked, self.total_unliked, self.total_followed,
                  self.total_unfollowed, self.total_commented,
                  self.total_blocked, self.total_unblocked, self.start_time)
  
  
  def save_checkpoint(self):
      cp = Checkpoint(self)
  
      with open(CHECKPOINT_PATH, 'wb') as f:
          pickle.dump(cp, f, -1)
      return True
  
  
  def load_checkpoint(self):
      try:
          with open(CHECKPOINT_PATH, 'rb') as f:
              cp = pickle.load(f)
          if isinstance(cp, Checkpoint):
              return cp.dump()
          else:
              os.remove(CHECKPOINT_PATH)
      except:
          pass
      return None
  
subject: fix doc string