Minimum Number of Arrows to Burst Balloons

You are given a list of balloons, each represented as a list `[x_start, x_end]` (inclusive). An arrow shot at position `x` bursts any balloon whose interval contains `x`. Write a function `findMinArrowShots(points)` that returns the minimum number of arrows needed to burst all balloons. Implement the function: ```python def findMinArrowShots(points: list[list[int]]) -> int: ``` **Input**: A list `points` where each element is a pair `[x_start, x_end]` with `0 <= x_start <= x_end <= 10^9`. The list may be empty. The number of balloons is at most 10^5. **Output**: An integer, the minimum number of arrows required.

>>> findMinArrowShots([[10,16],[2,8],[1,6],[7,12]])
2
>>> findMinArrowShots([[1,2],[3,4],[5,6],[7,8]])
4
>>> findMinArrowShots([[1,2],[2,3],[3,4],[4,5]])
2
>>> findMinArrowShots([])
0