Ferrugem•armanazi•erro•[e0046]: nem todos traço itens implementados, faltando: `summarize_author`

armanriazi•ferrugem•erro•[E0046]: nem todos traço itens implementados, faltando: `summarize_author`

//You must implement summarize_author and not only summarize
pub trait Summary {
    fn summarize(&self) -> String;
    fn summarize_author(&self) -> String;
}