How can i store the gemini model chat history of each chat

Brief description:what I want is for the user to create multiple chats, and also be able to continue the previous conversation.In the below code to continue with chat1 in chat3 I need a history how I can I store that history so that I can use it when I require it?

import osimport google.generativeai as genaiGOOGLE_API_KEY = os.environ.get('GOOGLE_API_KEY')genai.configure(api_key=GOOGLE_API_KEY)model = genai.GenerativeModel('gemini-pro')chat1 = model.start_chat(history=[])response = chat1.send_message("Which is asia's largest country?")response1 = chat1.send_message("What about it's capital?")response2 = chat1.send_message("What about it's population?")for message in chat1.history:    print(f'**{message.role}**: {message.parts[0].text}')print("*"*50)chat2 = model.start_chat(history=[])response = chat2.send_message("Which is india's capital?")response1 = chat2.send_message("What about it's population?")for message in chat2.history:    print(f'**{message.role}**: {message.parts[0].text}')print("*"*50)chat3 = model.start_chat(history=chat1.history)response = chat3.send_message("what's the name of it's currency?")for message in chat3.history:    print(f'**{message.role}**: {message.parts[0].text}')

I want the ways how can i store the chat history.

Note:I'm using django as framework and mysql as DB