In this exercise, you need to implement an inventory management system using stacks. The goal is to simulate real-world inventory operations, where products are managed in batches, and the Last-In-First-Out (LIFO) principle is applied. This approach mirrors scenarios where the most recently added inventory is used first, such as when dealing with durable goods.

Implement the Batch class (1 point)

Create the Batch class that represents a batch of inventory for a product. Each Batch object should contain:

• quantity: the quantity of the product in the batch
• cost_per_unit: cost for buying the product in this batch. This cost is not stored at the product level because it can differ from batch to batch.

The class also contains a tostring method str that represent the batch as follow:

Batch(quantity=[quantity], cost_per_unit=[self.cost_per_unit])

Implement the Product class (6 points):

Create the Products class (1 point) that represents a product with a stack of inventory batches. Every Product object should contain:

• product_name: name of the product
• batches: stack of batches for the product
• holding_cost: cost for holding a unit of the product in the inventory
• stockout_penalty: cost for not be able to deliver a unit of the product

This class should have the following methods:

• add_batch(quantity, cost_per_unit): add a new batch to the stack (1 point).
• fulfill_demand(demand): fulfills demand using the top batch of the inventory (2 points). If the top batch is not enough, the next batch is used. The function returns O if the demand can be fulfilled by one or more batches. If the demand cannot be fulfilled, the function returns stockout_penalty for the product multiplied by the number of products that cannot be delivered.
• calculate_holding_cost(): this function return the total holding cost for this product by adding the holding cost for every batch (1 point).

The class also contains a tostring method str (1 point) that represent the product as follows:

Product [product_name]:
Batch(quantity=[quantity_batch1 from batch_1], cost_per_unit=[cost_per_unit from batch_1])
Batch(quantity=[quantity_batch1 from batch_2], cost_per_unit=[cost_per_unit from batch_2])
....
Batch(quantity=[quantity_batch1 from batch_n], cost_per_unit=[cost_per_unit from batch_n])