> db.bar.insert({x:1})
> db.runCommand({find: "bar", filter: {"$where": "INVALID JAVASCRIPT!!!"}})
{
        "waitedMS" : NumberLong(0),
        "ok" : 0,
        "errmsg" : "Failed to call method",
        "code" : 1
}
> db.bar.find({$where: "INVALID JAVASCRIPT!!!!"})
Error: error: {
        "$err" : "Can't canonicalize query: InternalError Failed to call method",
        "code" : 17287
}