Your task in this homework assignment is to create a derived class that extends and overwrites attributes and methods in the base class.

Your solution to this problem must meet the following criteria.

1. Define a `Bank` class in `bank.py` python file that inherits the `Building` class.

1. You must define a constructor that accepts four arguments:

* an integer for `size` with a default value of 10000

* a float for `cost` with a default value of 2000000

1. You must define an dictionary attribute in `Bank` called `client_list`.

1. You must define a `add_client_deposit` instance method that takes two parameters:

* a string for the client name (the dictionary key)

* a float for the deposit amount (the dictionary value)

The `client_list` should be updated with new clients or have existing clients balance updated.

1. You must define a `cash_on_hand` instance method returns the total amount of money in the back.

Use the `client_list`'s values to determine value.

1. You must extend the `__str__` special method to append bank details in addition to the building as shown below.

1. The file `bank.py` should not contain a main program, it should only contain your class.

To test your class, add code to the `bank_test.py` file.

Note that code in `bank_test.py` will not be graded.

1. Below are example calls `Bank` methods which you could implement in `bank_test.py` to test your method.

Python Code:

```python

import bank

test_bank = bank.Bank(25000, 2500000)

print(test_bank)

test_bank.add_client_deposit("Jack Sparrow", 50000)

test_bank.add_client_deposit("Johns Tip", 250)

print(test_bank.cash_on_hand())

test_bank.add_client_deposit("Johns Tip", 10)

print(test_bank.cash_on_hand())

```

Output:

```html

The build is 25000 square ft and costs $2500000.

The building is a bank with $0 cash on hand.

50250

50260

```

edit:

class Building:

def __init__(self, size=2500, cost=600000):

self.size = size

self.cost = cost

def __str__(self):

return "The build is {} square ft and costs ${}.".format(self.size, self.cost)