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

The minimum absolute difference of an array a is defined as the minimum value of |a[i] - a[j]|, where 0 <= i < j < a.length and a[i] != a[j]. If all elements of a are the same, the minimum absolute difference is -1.

For example, the minimum absolute difference of the array [5,2,3,7,2] is |2 - 3| = 1. Note that it is not 0 because a[i] and a[j] must be different.

You are given an integer array nums and the array queries where queries[i] = [li, ri]. For each query i, compute the minimum absolute difference of the subarray nums[li...ri] containing the elements of nums between the 0-based indices li and ri (inclusive).
Return an array ans where ans[i] is the answer to the ith query.
A subarray is a contiguous sequence of elements in an array.
The value of |x| is defined as:

x if x >= 0.
-x if x < 0.

 
Please complete the following python code precisely:
```python
class Solution:
    def minDifference(self, nums: List[int], queries: List[List[int]]) -> List[int]:
```