Please solve the programming task below using a self-contained code snippet in a markdown code block.

A perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. A divisor of an integer x is an integer that can divide x evenly.
Given an integer n, return true if n is a perfect number, otherwise return false.
 
Please complete the following python code precisely:
```python
class Solution:
    def checkPerfectNumber(self, num: int) -> bool:
```