pub fn supertrend(
high: &[f64],
low: &[f64],
close: &[f64],
params: SupertrendParams,
) -> FinanceResult<SupertrendSeries>pub fn supertrend(
high: &[f64],
low: &[f64],
close: &[f64],
params: SupertrendParams,
) -> FinanceResult<SupertrendSeries>