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

Alice has some number of cards and she wants to rearrange the cards into groups so that each group is of size groupSize, and consists of groupSize consecutive cards.
Given an integer array hand where hand[i] is the value written on the ith card and an integer groupSize, return true if she can rearrange the cards, or false otherwise.
 
Please complete the following python code precisely:
```python
class Solution:
    def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:
```