Function likely_duplicates 

pub async fn likely_duplicates(
    pool: &PgPool,
    actor: &Actor,
    name: &str,
    item_type: Option<ItemType>,
    exclude: Option<Uuid>,
    limit: usize,
) -> AppResult<Vec<Duplicate>>

The items most similar to name (best first, at most limit), of the same type when one is given; exclude leaves out an item (the one just created).