code: def get_stored_version(connection):
      
  
      if connection.engine.name == 'sqlite':
          version = connection.execute('PRAGMA user_version').fetchone()[0]
          if version == 0:
              raise VersionIsNotStored
          return version
      elif connection.engine.name == 'postgresql':
          try:
              r = connection\
                  .execute('SELECT version FROM {}.user_version;'.format(POSTGRES_SCHEMA_NAME))\
                  .fetchone()
              if not r:
                  raise VersionIsNotStored
  
              version = r[0]
  
          except ProgrammingError:
              # This happens when the user_version table doesn't exist
              raise VersionIsNotStored
          return version
      else:
          raise DatabaseError('Do not know how to get version from {} engine.'.format(connection.engine.name))
docs: Returns database version.
  
      Args:
          connection (sqlalchemy connection):
  
      Raises: Assuming user_version pragma (sqlite case) and user_version table (postgresql case)
          exist because they created with the database creation.
  
      Returns:
          int: version of the database.