old_contents: """emory database class for chattimarkov.
  
  This is just a volatile, in-memory database which is built either from a
  pre-existing dictionary or from scratch. Upon object destruction, the database
  is not saved.
  """
  
  import random
  
  from .base import AbstractDatabase
  
  
  class MemoryDatabase(AbstractDatabase):
      def __init__(self, db=None):
          if db is None:
              self.db = {}
          else:
              self.db = db
  
      def add(self, key, element):
          if key not in self.db:
              self.db[key] = []
          if type(self.db[key]) is not list:
              return False
  
          if element not in self.db[key]:
              self.db[key].append(element)
  
      def random(self, key):
          if key not in self.db:
              return None
          if type(self.db[key]) is not list:
              return None
          return random.choice(self.db[key])
  
      def get(self, key, default=None):
          return self.db.get(key, default)
  
      def set(self, key, value):
          self.db[key] = value
  
new_contents: """Memory database class for chattimarkov.
  
  This is just a volatile, in-memory database which is built either from a
  pre-existing dictionary or from scratch. Upon object destruction, the database
  is not saved.
  """
  
  import random
  
  from .base import AbstractDatabase
  
  
  class MemoryDatabase(AbstractDatabase):
      def __init__(self, db=None):
          if db is None:
              self.db = {}
          else:
              self.db = db
  
      def add(self, key, element):
          if key not in self.db:
              self.db[key] = []
          if type(self.db[key]) is not list:
              return False
  
          if element not in self.db[key]:
              self.db[key].append(element)
  
      def random(self, key):
          if key not in self.db:
              return None
          if type(self.db[key]) is not list:
              return None
          return random.choice(self.db[key])
  
      def get(self, key, default=None):
          return self.db.get(key, default)
  
      def set(self, key, value):
          self.db[key] = value
  
subject: Fix typo in docstring