Why are there two q_net in the sac2018.py file?

[TianQi-777]

This is a great job :)

I am confused about sac2018.py implementation，Why are there two q_net in the sac2018.py file? (code link)
I did not see this description in the original paper Soft Actor-Critic: Off-Policy Maximum Entropy Deep Reinforcement Learning with a Stochastic Actor

In addition, I want to verify one thing. If I understand correctly, sac2018.py is the implementation of Soft Actor-Critic: Off-Policy Maximum Entropy Deep Reinforcement Learning with a Stochastic Actor, and sac2019.py is the implementation of Soft Actor-Critic Algorithms and Applications. Looking forward to your reply.

[TianQi-777]

sorry, I found it in the paper!