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

You are given an integer n and an integer start.
Define an array nums where nums[i] = start + 2 * i (0-indexed) and n == nums.length.
Return the bitwise XOR of all elements of nums.
 
Please complete the following python code precisely:
```python
class Solution:
    def xorOperation(self, n: int, start: int) -> int:
```