[Lab_3] Fix crashes during cleanup of non-existent objects
[Lab_3] Fix crashes during cleanup of non-existent objects

viviken/HSE_AI_Labs,akashin/HSE_AI_Labs,akashin/HSE_AI_Labs,akashin/HSE_AI_Labs,akashin/HSE_AI_Labs,akashin/HSE_AI_Labs,viviken/HSE_AI_Labs,akashin/HSE_AI_Labs,viviken/HSE_AI_Labs,viviken/HSE_AI_Labs,akashin/HSE_AI_Labs