code: def verify_checksum(message, previous_csum=0):
      
      if message.message_type in CHECKSUM_MSG_TYPES:
          csum = compute_checksum(
              message.checksum[0],
              message.args,
              previous_csum,
          )
  
          if csum == message.checksum[1]:
              return True
          else:
              return False
      else:
          return True
docs: Verify checksum for incoming message.
  
      :param message: incoming message
      :param previous_csum: accumulated checksum value
  
      :return return True if message checksum type is None
      or checksum is correct