hasOneThrough(Brand::class, CarModel::class); } public function carModel() { return $this->belongsTo(CarModel::class); } public function seller() { return $this->belongsTo(Contact::class, 'seller_contact_id'); } public function buyer() { return $this->hasOneThrough(Contract::class, Contact::class); } public function contract() { return $this->hasOne(Contract::class); } public function carPayment() { return $this->hasManyThrough(CarPayment::class, Contract::class); } }