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

You are given an integer array nums and two integers indexDiff and valueDiff.
Find a pair of indices (i, j) such that:

i != j,
abs(i - j) <= indexDiff.
abs(nums[i] - nums[j]) <= valueDiff, and

Return true if such pair exists or false otherwise.
 
Please complete the following python code precisely:
```python
class Solution:
    def containsNearbyAlmostDuplicate(self, nums: List[int], indexDiff: int, valueDiff: int) -> bool:
```