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

Given two strings s and part, perform the following operation on s until all occurrences of the substring part are removed:

Find the leftmost occurrence of the substring part and remove it from s.

Return s after removing all occurrences of part.
A substring is a contiguous sequence of characters in a string.
 
Please complete the following python code precisely:
```python
class Solution:
    def removeOccurrences(self, s: str, part: str) -> str:
```