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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_columns_relevant_for_diff(columns_to_show):
 """ Extract columns that are relevant for the diff table. @param columns_to_show: (list) A list of columns that should be shown @return: (set) Set of columns that are relevant for the diff table. If none is marked relevant, the column named "status" will be returned in the set. """

    cols = set([col.title for col in columns_to_show if col.relevant_for_diff])
    if len(cols) == 0:
        return set(
            [col.title for col in columns_to_show if col.title == "status"])
    else:
        return cols