Создать новый массив с объектами с уникальными свойствами

gistfile1.txt

var districts = [];
function removeDuplicateDistricts(cities) {
    for (let i = 0; i < cities.length; i++) {
        if (districts.length === 0) {
            districts.push(cities[0]);
        } else {
            var uniqueDistrict = true;
            districts.forEach(function(dist) {
                if (cities[i].Region == dist.Region && cities[i].District == dist.District) {
                    uniqueDistrict = false;
                }
            });
            if (uniqueDistrict) {
                districts.push(cities[i]);
            }
        }
    }
}