pub async fn start<DB: DbMarker>(
        self,
        storage: &'a mut Connection<'_, DB>,
    ) -> DalResult<ActiveCopy<'a>> {
        let (conn, tags) = storage.conn_and_tags();
        match conn.copy_in_raw(self.query.statement).await {
            Ok(raw) => Ok(ActiveCopy {
                raw,
                data: self.data,
                tags,
            }),
            Err(err) => Err(
                DalRequestError::new(err, self.data.name, self.data.location)
                    .with_args(self.data.args.to_owned())
                    .with_connection_tags(tags.cloned())
                    .into(),
            ),
        }
    }
Starts `COPY`ing data using this statement.
core/lib/db_connection/src/instrument.rs