fun Map<Int, Int>.toPlotData(xTitle: String, yTitle: String): Map<String, List<Int>> {
    val plotPoints = this.entries
        .sortedBy { it.key }
        .fold(Pair(mutableListOf<Int>(), mutableListOf<Int>())) { acc, (k, v) ->
            acc.first += k
            acc.second += v
            acc
        }
    return mapOf(
        xTitle to plotPoints.first,
        yTitle to plotPoints.second
    )
}