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

Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the result in any order.
 
Please complete the following python code precisely:
```python
class Solution:
    def intersection(self, nums1: List[int], nums2: List[int]) -> List[int]:
```