arangosh> a1 = db.example.insert({ a : 1 });
{
"_id" : "example/15746",
"_key" : "15746",
"_rev" : "15746"
}
arangosh> a2 = db.example.replace(a1, { a : 2 });
{
"_id" : "example/15746",
"_key" : "15746",
"_rev" : "15750",
"_oldRev" : "15746"
}
arangosh> a3 = db.example.replace(a1, { a : 3 });
[ArangoError 1200: precondition failed]