+ @property
+ def fingerprint(self):
+ assert len(self.fingerprints) == 1
+ return self.fingerprints[0]
+
+ @property
+ def primary_fingerprint(self):
+ assert len(self.primary_fingerprints) == 1
+ return self.primary_fingerprints[0]
+
+ @property
+ def signature_id(self):
+ assert len(self.signature_ids) == 1
+ return self.signature_ids[0]
+