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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 _validate_usecols_names(usecols, names):
 """ Validates that all usecols are present in a given list of names. If not, raise a ValueError that shows what usecols are missing. Parameters usecols : iterable of usecols The columns to validate are present in names. names : iterable of names The column names to check against. Returns ------- usecols : iterable of usecols The `usecols` parameter if the validation succeeds. Raises ------ ValueError : Columns were missing. Error message will list them. """

    missing = [c for c in usecols if c not in names]
    if len(missing) > 0:
        raise ValueError(
            "Usecols do not match columns, "
            "columns expected but not found: {missing}".format(missing=missing)
        )

    return usecols