cosmos-rust-getting-started-db-update

db.rs

fn update(&self, filter: Document, update: Document) -> Result<Option<i64>, Error> {
   let collection = &self
      .client
      .get_db(&self.database)
      .get_collection(&self.collection);

   match collection.update_one(filter, update, None) {
      Ok(result) => Ok(Some(result.modified_count)),
      Err(e) => Err(e),
   }
}