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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 is_id_only(self):
 """Return True if identifier information only."""

        for key, value in self.items():
            if key not in {'names', 'labels', 'roles'} and value:
                return False
        if self.names or self.labels:
            return True
        return False