pub trait ModelStore {
// Required methods
fn map_add(&mut self, model_name: &str, prefix: &str, v: f64) -> f64;
fn map_add_with_default(
&mut self,
model_name: &str,
prefix: &str,
v: f64,
default: f64,
) -> f64;
fn map_get(&self, model_name: &str, prefix: &str) -> f64;
fn save_class(&mut self, model_name: &str, class: &str);
fn get_all_classes(&self, model_name: &str) -> Option<BTreeSet<String>>;
}