arango> db.example.save({"a" : 1});
{ "error" : false, "_id" : "example/19988371", "_key" : "19988371", "_rev" : "19988371" }
arango> db.example.update("example/19988371", { "b" : null, "c" : null, "d" : 3 });
{ "error" : false, "_id" : "example/19988371", "_key" : "19988371", "_rev" : "20119443" }
arango> db.example.document("example/19988371");
{ "b" : null, "c" : null, "a" : 1, "d" : 3, "_id" : "example/19988371", "_key" : "19988371", "_rev" : "20119443" }

arango> db.example.update("example/19988371", { "a" : null }, false, false);
{ "error" : false, "_id" : "example/19988371", "_key" : "19988371", "_rev" : "20250515" }
arango> db.example.document("example/19988371");
{ "b" : null, "c" : null, "d" : 3, "_id" : "example/19988371", "_key" : "19988371", "_rev" : "20250515" }
arango> db.example.update("example/19988371", { "b" : null, "c": null, "d" : null }, false, false);
{ "error" : false, "_id" : "example/19988371", "_key" : "19988371", "_rev" : "20381587" }
arango> db.example.document("example/19988371");
{ "_id" : "example/19988371", "_key" : "19988371", "_rev" : "20381587" }