test_that("errors calling knnmodel function", {
  expect_error(knn_model(ts(1:5), lags = 0:3, k = 5))
  expect_error(knn_model(ts(1:5), lags = 3:5, k = 1))
  expect_error(knn_model(ts(1:5), lags = 2:4, k = 2))
})