+
+t2:
+ id: 1
+ member_role: "some"
+ member_type: "Node"
+ member_id: 5
+
+t3:
+ id: 1
+ member_role: "some"
+ member_type: "Relation"
+ member_id: 3
+
+t4:
+ id: 3
+ member_role: "some"
+ member_type: "Node"
+ member_id: 5
+
+t5:
+ id: 2
+ member_role: "some"
+ member_type: "Node"
+ member_id: 5
+
+public_used:
+ id: 6
+ member_role: "used by other relation"
+ member_type: "Relation"
+ member_id: 5