Your task is to implement the following requirements and cover at least 80% of your code with JUnit tests. All input data will be passed in the file in CSV format.

Let's imagine you have a fruit store. There are three type of operations in your fruit store:

    s - supply, means you are receiving a new fruits from suppliers
    b - buy, means someone bought a fruit
    r - return, means someone who have bought the fruits now returns you it

Let's check in details all types of operations:

1. Supply. You are accepting a new fruit from suppliers. The following line in the file will look like:

      s,banana,100,2020-10-17     
   

   The line above means you receive a 100 bananas, and their expiration date is 17-th October 2020.

2. Buy. Buyers can visit your shop and buy some fruits. In this case you will have the following line in the file:

      b,banana,13,2020-10-15     
   

   The line above means someone bought a 13 bananas. Date of purchase is 15-th October 2020.

3. Return. Buyers can return you some fruits. In this case you will have the following line in the file:

      r,banana,10,2020-10-17     
   

   The line above means someone return you a 10 bananas, and their expiration date is 17-th October 2020.

    type,fruit,quantity,date
    s,banana,100,2020-10-17
    b,banana,13,2020-10-15
    r,banana,10,2020-10-17 

We are expecting to see how many fruits are available in your Fruit store after the file processing. For example:

    fruit,quantity
    banana,97
    orange,147
    apple,29

The line above means you have 97 bananas, 147 oranges and 29 apples in your Fruit store.

ADVANCED:

• Keep in mind Open-Closed Principle (from SOLID) when you will do this task