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

Given a string s and a string array dictionary, return the longest string in the dictionary that can be formed by deleting some of the given string characters. If there is more than one possible result, return the longest word with the smallest lexicographical order. If there is no possible result, return the empty string.
 
Please complete the following python code precisely:
```python
class Solution:
    def findLongestWord(self, s: str, dictionary: List[str]) -> str:
```