def oucru_convert_dtypes(tidy, columns=[]):
    """Helper method to apply convert_dtypes.

    Helper method to apply convert_dtypes() to a specific
    set of columns which might or might not be included
    in the DataFrame.

    Parameters
    ----------
    tidy: pd.DataFrame
        The DataFrame
    columns: list
        The columns to apply convert_dtypes()

    Returns
    -------
    pd.DataFrame
        The DataFrame with columns converted.

    """
    # Find intersection
    intersection = \
        list(set(columns).intersection(tidy.columns))

    # The intersection is empty
    if not intersection:
        return tidy

    # Convert dtypes
    tidy[intersection] = \
        tidy[intersection].convert_dtypes()

    # Return
    return tidy