pub trait Vocabulary: Sync + Debug {
// Required methods
fn get_max_token_type(&self) -> isize;
fn get_literal_name(&self, token_type: isize) -> Option<&str>;
fn get_symbolic_name(&self, token_type: isize) -> Option<&str>;
fn get_display_name(&self, token_type: isize) -> Cow<'_, str>;
}