def METHOD_NAME(self):
    """Check for duplication in the schema"""
    labels = [
        _record["rdfs:label"]
        for _record in self.extension_schema["schema"]["@graph"]
    ]
    duplicates = find_duplicates(labels)
    try:
        assert len(duplicates) == 0
    except:
        raise Exception("Duplicates detected in graph: ", duplicates)