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

Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.
Your task is to find the smallest possible length of a (contiguous) subarray of nums, that has the same degree as nums.
 
Please complete the following python code precisely:
```python
class Solution:
    def findShortestSubArray(self, nums: List[int]) -> int:
```