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

A ramp in an integer array nums is a pair (i, j) for which i < j and nums[i] <= nums[j]. The width of such a ramp is j - i.
Given an integer array nums, return the maximum width of a ramp in nums. If there is no ramp in nums, return 0.
 
Please complete the following python code precisely:
```python
class Solution:
    def maxWidthRamp(self, nums: List[int]) -> int:
```