largestRectangleArea = function(heights) {
    const { stack, maxArea } = fillStack(heights);        /* Time O(N) | Space O(N) */

    return getMaxArea(heights, stack, maxArea);           /* Time O(N) */
}
https://leetcode.com/problems/largest-rectangle-in-histogram/solution/
Time O(N) | Space O(N)
@param {number[]} heights
@return {number}