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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 evaluate_report(report):
 """Iterate over validation errors."""

        if report["valid"]:
            return
        for warn in report["warnings"]:
            LOGGER.warning(warn)
        # We only ever test one table at a time.
        for err in report["tables"][0]["errors"]:
            LOGGER.error(err["message"])
        raise ValueError("Invalid data file. Please see errors above.")