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

You are given an array coordinates, coordinates[i] = [x, y], where [x, y] represents the coordinate of a point. Check if these points make a straight line in the XY plane.
 
 
Please complete the following python code precisely:
```python
class Solution:
    def checkStraightLine(self, coordinates: List[List[int]]) -> bool:
```