pub trait AnyVec: Send + Sync {
// Required methods
fn version(&self) -> Version;
fn name(&self) -> String;
fn len(&self) -> usize;
fn modified_time(&self) -> Result<Duration>;
fn index_type_to_string(&self) -> String;
fn value_type_to_size_of(&self) -> usize;
// Provided method
fn is_empty(&self) -> bool { ... }
}