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

Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string "".
The testcases will be generated such that the answer is unique.
 
Please complete the following python code precisely:
```python
class Solution:
    def minWindow(self, s: str, t: str) -> str:
```