arangosh> db._create("users", { keyOptions: { type: "autoincrement", offset: 10, increment: 5 } });
[ArangoCollection 111044054, "users" (type document, status loaded)]
arangosh> db.users.save({ name: "user 1" });
{ 
  "error" : false, 
  "_id" : "users/10", 
  "_rev" : "111371734", 
  "_key" : "10" 
}
arangosh> db.users.save({ name: "user 2" });
{ 
  "error" : false, 
  "_id" : "users/15", 
  "_rev" : "111568342", 
  "_key" : "15" 
}
arangosh> db.users.save({ name: "user 3" });
{ 
  "error" : false, 
  "_id" : "users/20", 
  "_rev" : "111764950", 
  "_key" : "20" 
}