Illuminate\\Database\\Eloquent\\MassAssignmentException: Add [cp_listing_id] to fillable property code example

Example: "Illuminate\Database\Eloquent\MassAssignmentException"

//Laravel provides by default a protection against mass assignment security issues. 
//That's why you have to manually define which fields could be "mass assigned" :
class User extends Model
{
    protected $fillable = ['username', 'email', 'password'];
}