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

Given a sentence that consists of some words separated by a single space, and a searchWord, check if searchWord is a prefix of any word in sentence.
Return the index of the word in sentence (1-indexed) where searchWord is a prefix of this word. If searchWord is a prefix of more than one word, return the index of the first word (minimum index). If there is no such word return -1.
A prefix of a string s is any leading contiguous substring of s.
 
Please complete the following python code precisely:
```python
class Solution:
    def isPrefixOfWord(self, sentence: str, searchWord: str) -> int:
```