arangosh> db.example.save({ Hello : "world", foo : "bar" });
{ 
  "_id" : "example/450817260", 
  "_rev" : "450817260", 
  "_key" : "450817260" 
}
arangosh> db.example.updateByExample({ Hello: "world" }, { Hello: "foo", World: "bar" }, false);
1
arangosh> db.example.byExample({ Hello: "foo" }).toArray()
[ 
  { 
    "_id" : "example/450817260", 
    "_key" : "450817260", 
    "_rev" : "451144940", 
    "Hello" : "foo", 
    "foo" : "bar", 
    "World" : "bar" 
  } 
]