*Debug*   function `getSumOfDigits` that takes positive integer to calculate sum of it's digits. Assume that argument is an integer.
### Example
```
123  => 6
223  => 7
1337 => 15
```
def get_sum_of_digits(num):
    digits = []
    for i in str(num): digits.append(int(i))
    return sum(digits)
def get_sum_of_digits(num):
    digits = []
    for i in str(num): digits.append(int(i))
    return sum(digits)