attribute doesn't add in stdClass object - php

Question

I am developing a web application in laravel 5.3. The problem i am getting is that attributes doesn't add up in stdClass object, however you can see my code where i am explicitly setting/adding a new attributes in a object.
problematic code
1- $sender = Sender::where('id', $this->senderId)->first();
2- if ($sender != null) {
3- var_dump($sender->bundle);
4- $sender->bundle->latitude = $this->lat;
5- $sender->bundle->longitude = $this->long;
6- $sender->bundle->location = $response->formattedAddress();
7- var_dump($sender->bundle);
8- $sender->save();
9- error_log('resolved');
10- } else {
11- error_log('no sender');
12- }
In above code you can clearly see that i am setting some new properties for bundle object.
$sender->bundle->latitude = $this->lat;
$sender->bundle->longitude = $this->long;
$sender->bundle->location = $response->formattedAddress();
but in output you can clearly see that it doesn't get add up. The code basically runs in laravel queue. In above code $sender is laravel eloquent model and the attribute bundle is being json_decode via laravel mutators.
mutator code
public function setBundleAttribute($value) {
$this->attributes['bundle'] = json_encode($value);
}
public function getBundleAttribute($value) {
return json_decode($value);
}
output of above problematic code
object(stdClass)#686 (3) { #output of line 3
["city"]=>
string(0) ""
["province"]=>
string(0) ""
["country"]=>
string(0) ""
}
object(stdClass)#686 (3) { #output of line 7
["city"]=>
string(0) ""
["province"]=>
string(0) ""
["country"]=>
string(0) ""
}
[2017-07-25 16:11:03] Processed: App\Jobs\LocationResolverQueue
resolved
Problem Solved
laravel Accessors & Mutators cause the problem.
Accessor and Mutator get called whenever we get or set property respectively, in my case the mutator was calling whenever i try to access $sender->bundle->property however accessor didn't get called because i was setting a $sender->bundle->property rather than $sender->bundle
i solved problem like
$sender = Sender::where('id', $this->senderId)->first();
if ($sender != null) {
$temp = $sender->bundle;
$temp->latitude = $this->lat;
$temp->longitude = $this->long;
$temp->location = $response->formattedAddress();
$sender->bundle = $temp;
$sender->save();
}