use finance_solution::stocks::ta::{keltner_solution, KeltnerParams};
let n = 30usize;
let high: Vec<_> = (0..n).map(|i| 11.0 + i as f64).collect();
let low: Vec<_> = (0..n).map(|i| 9.0 + i as f64).collect();
let close: Vec<_> = (0..n).map(|i| 10.0 + i as f64).collect();
let sol = keltner_solution(&high, &low, &close, KeltnerParams::standard()).unwrap();
assert!(sol.formula().contains("Wilder"));