constructor () {
        this.maxHeap = new MaxPriorityQueue()
        this.minHeap = new MinPriorityQueue()
    }
https://leetcode.com/problems/find-median-from-data-stream/
Your MedianFinder object will be instantiated and called as such:
var obj = new MedianFinder()
obj.addNum(num)
var param_2 = obj.findMedian()