Iterate over all triples in the graph and validate each one
            appropriately

def validate(self):
        """Iterate over all triples in the graph and validate each one
            appropriately
        """
        log.info("{}\nValidating against {}"
                 .format("-" * 100, self.schema_def.__class__.__name__))

        if not self.schema_def:
            raise ValueError("No schema definition supplied.")

        self.checked_attributes = []

        # TODO - this should maybe choose the actually used namespace, not just
        # the first one in the list
        result = ValidationResult(self.allowed_namespaces[0],
                                  self.schema_def.__class__.__name__)
        for subject, predicate, object_ in self.graph:
            log.info("\nsubj: {subj}\npred: {pred}\n obj: {obj}"
                     .format(subj=subject, pred=predicate,
                             obj=object_.encode('utf-8')))
            result.add_error(self._check_triple((subject, predicate, object_)))
        return result