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

A subarray of a 0-indexed integer array is a contiguous non-empty sequence of elements within an array.
The alternating subarray sum of a subarray that ranges from index i to j (inclusive, 0 <= i <= j < nums.length) is nums[i] - nums[i+1] + nums[i+2] - ... +/- nums[j].
Given a 0-indexed integer array nums, return the maximum alternating subarray sum of any subarray of nums.
 
Please complete the following python code precisely:
```python
class Solution:
    def maximumAlternatingSubarraySum(self, nums: List[int]) -> int:
```