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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_document(self, definition):
 """ Validate given pipeline document. The method is trying to load, parse and validate the spline document. The validator verifies the Python structure B{not} the file format. Args: definition (str):
 path and filename of a yaml file containing a valid spline definition. Returns: dict: loaded and validated spline document. Note: if validation fails the application does exit! See Also: spline.validation.Validator """

        initial_document = {}
        try:
            initial_document = Loader.load(definition)
        except RuntimeError as exception:
            self.logger.error(str(exception))
            sys.exit(1)

        document = Validator().validate(initial_document)
        if document is None:
            self.logger.info("Schema validation for '%s' has failed", definition)
            sys.exit(1)
        self.logger.info("Schema validation for '%s' succeeded", definition)
        return document