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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 ensure_chosen_alternatives_are_in_user_alt_ids(choice_col, wide_data, availability_vars):
 """ Ensures that all chosen alternatives in `wide_df` are present in the `availability_vars` dict. Raises a helpful ValueError if not. Parameters choice_col : str. Denotes the column in `wide_data` that contains a one if the alternative pertaining to the given row was the observed outcome for the observation pertaining to the given row and a zero otherwise. wide_data : pandas dataframe. Contains one row for each observation. Should contain the specified `choice_col` column. availability_vars : dict. There should be one key value pair for each alternative that is observed in the dataset. Each key should be the alternative id for the alternative, and the value should be the column heading in `wide_data` that denotes (using ones and zeros) whether an alternative is available/unavailable, respectively, for a given observation. Alternative id's, i.e. the keys, must be integers. Returns ------- None. """

    if not wide_data[choice_col].isin(availability_vars.keys()).all():
        msg = "One or more values in wide_data[choice_col] is not in the user "
        msg_2 = "provided alternative ids in availability_vars.keys()"
        raise ValueError(msg + msg_2)

    return None