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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_yaml(self, properties):
 """Validate the parsed YAML file for adherance to the ChemKED format. Arguments: properties (`dict`):
 Dictionary created from the parsed YAML file Raises: `ValueError`: If the YAML file cannot be validated, a `ValueError` is raised whose string contains the errors that are present. """

        validator = OurValidator(schema)
        if not validator.validate(properties):
            for key, value in validator.errors.items():
                if any(['unallowed value' in v for v in value]):
                    print(('{key} has an illegal value. Allowed values are {values} and are case '
                           'sensitive.').format(key=key, values=schema[key]['allowed']))

            raise ValueError(validator.errors)