arangosh> db._create("users", { keyOptions: { allowUserKeys: false } });
[ArangoCollection 73720, "users" (type document, status loaded)]
arangosh> db.users.save({ name: "user 1" });
{
"_id" : "users/73725",
"_key" : "73725",
"_rev" : "_ZXF6cxq--A"
}
arangosh> db.users.save({ name: "user 2", _key: "myuser" });
[ArangoError 1222: unexpected document key]
arangosh> db.users.save({ name: "user 3" });
{
"_id" : "users/73728",
"_key" : "73728",
"_rev" : "_ZXF6cxu---"
}