arango> v1 = db.vertex.save({ name : "vertex 1" });
{ "_id" : "vertex/1528086", "_key" : "1528086", "_rev" : "1528086" }
arango> v2 = db.vertex.save({ name : "vertex 2" });
{ "_id" : "vertex/1593622", "_key" : "1593622", "_rev" : "1593622" }
arango> e1 = db.relation.save(v1, v2, { label : "knows" });
{ "_id" : "relation/3100950", "_key" : "3100950", "_rev" : "3100950" }
arango> db._document(e1);
{ "_id" : "relation/3100950", "_key" : "3100950", "_rev" : "3100950", "_from" : "vertex/1528086", "_to" : "vertex/1593622", "label" : "knows" }