///|
fn main {
  let dataset = @tree.regression_dataset([[0.0], [1.0], [2.0], [3.0]], [
    0.0, 2.0, 4.0, 6.0,
  ]).unwrap()
  let model = @tree.train_regressor(dataset, @tree.RegressionConfig::default()).unwrap()
  let predictions = model.predict_batch([[0.0], [2.0], [3.0]]).unwrap()
  println("p0=\{predictions[0]}, p1=\{predictions[1]}, p2=\{predictions[2]}")
  let importance = model.feature_importance()
  println("feature0=\{importance[0]}")
}