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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 check_dataframe_for_duplicate_records(obs_id_col, alt_id_col, df):
 """ Checks a cross-sectional dataframe of long-format data for duplicate observations. Duplicate observations are defined as rows with the same observation id value and the same alternative id value. Parameters obs_id_col : str. Denotes the column in `df` that contains the observation ID values for each row. alt_id_col : str. Denotes the column in `df` that contains the alternative ID values for each row. df : pandas dataframe. The dataframe of long format data that is to be checked for duplicates. Returns ------- None. """

    if df.duplicated(subset=[obs_id_col, alt_id_col]).any():
        msg = "One or more observation-alternative_id pairs is not unique."
        raise ValueError(msg)

    return None