pub trait ModelEstimator {
// Required methods
fn mu_direct(&self) -> Result<Array1<f64>, ApiError>;
fn estimate(
&self,
etype: Estimator,
key: &str,
i_export: usize,
) -> Result<f64, ApiError>;
fn estimate_time(
&self,
etype: Estimator,
key: &str,
) -> Result<Array1<f64>, ApiError>;
}