bitcoin core – How can I load a specific private key into my wallet

Starting a Private Node using bitcoin-qt.

And then I generate a pair of keys for my own testing.

But unfortunately whenever I reset the node, it will generate a new pairs of keys, it makes my recursive test very tedious.

Is there a way for me to load a private key into my wallet instead of using getnewaddress every time and test with a new pair of keys?