Your task is to create an E-commerce system that can perform the following functions: 1. Manage Products: The system should be capable of adding new products, deleting existing products, and searching for products by various attributes (e.g., name, category). Each product should have attributes such as name, price, category, and stock count. 2. Manage Users: The system should be able to add new users (both customers and sellers), delete users, and manage user information. Each user should have attributes such as name, email, and password. Sellers should have a list of products they're selling. 3. Shopping Cart & Purchasing: Users should be able to add products to a shopping cart, view the contents of the cart, and make a purchase. After a purchase, the system should update the stock count of the products and the list of products owned by the user. 4. Order History: Users should be able to view their past orders, including the products purchased and the total price. 5. User Interface: Implement a simple text-based user interface for users to interact with the system. The interface should provide options for all the features described above. Requirements: 1. Use object-oriented programming principles. 2. Write clear, understandable code with appropriate comments. 3. Handle potential exceptions and edge cases. For instance, what happens if a product is out of stock, or a user enters incorrect login credentials? 4. Implement unit tests to ensure your code works as expected. Deliverables: 1. Source Code: The complete source code of your project. It should be well-structured and commented. 2. Documentation: A document that includes: - An overview of your project. - A description of how your system works. - Instructions on how to run your system. - Any assumptions you made while developing the system.