Error in `predict_and_evaluate(data)`: object 'small_model' not found

test_that("SLOS generates expected outputs", {
test_that("SLOS handles empty or invalid data", {
expect_error(SLOS(data.frame()), "Error: Input data must contain at least one row.")
invalid_data <- data.frame(InvalidColumn = c(1, 2, 3))
expect_error(SLOS(invalid_data), "Error: Missing required columns: UnitCode, UnitLengthStay_trunc")

"Error: Input data must contain at least one row."
"Error: Missing required columns: UnitCode, UnitLengthStay_trunc"

Error in `predict_and_evaluate(sampled_data)`: object 'small_model' not found

test_that("predict_and_evaluate works as expected", {
expect_named(result, c("predictions", "comparison", "RMSE", "MAE", "R2"))