public function dataProviderForR2()
{
return [[[[1, 2], [2, 3], [4, 5], [5, 7], [6, 8]], 0.986049], [[[4, 390], [9, 580], [10, 650], [14, 730], [4, 410], [7, 530], [12, 600], [22, 790], [1, 350], [3, 400], [8, 590], [11, 640], [5, 450], [6, 520], [10, 690], [11, 690], [16, 770], [13, 700], [13, 730], [10, 640]], 0.87160896]];
}