def METHOD_NAME(dataset: DataSet,
                                    target_conn: ConnectionPlus,
                                    target_exp_id: int) -> None:
    """
    NB: This function should only be called from within
    meth:`extract_runs_into_db`
    Insert the given dataset into the specified database file as the latest
    run.
    Trying to insert a run already in the DB is a NOOP.
    Args:
        dataset: A dataset representing the run to be copied
        target_conn: connection to the DB. Must be atomically guarded
        target_exp_id: The ``exp_id`` of the (target DB) experiment in which to
          insert the run
    """
    if not dataset.completed:
        raise ValueError('Dataset not completed. An incomplete dataset '
                         'can not be copied. The incomplete dataset has '
                         f'GUID: {dataset.guid} and run_id: {dataset.run_id}')
    source_conn = dataset.conn
    run_id = get_runid_from_guid(target_conn, dataset.guid)
    if run_id is not None:
        return
    _, _, target_table_name = _add_run_to_runs_table(
        dataset, target_conn, target_exp_id
    )
    assert target_table_name is not None
    _populate_results_table(
        source_conn, target_conn, dataset.table_name, target_table_name
    )