将Eloquent \ Builder作为参数传递

Probably it's an easy answer, but I don't find it! I'm using Eloquent to perform my queries into the database, having this code:

public function postSearch(Request $request)
{
    $query = Customer::select('identification', 'first_name', 'second_name', 'first_lastname', 'second_lastname', 'genre')
                ->where('identification', 'LIKE', "%$request->identification%")
                ->where('first_name', 'LIKE', "%$request->first_name%")
                ->Where('second_name', 'LIKE', "%$request->second_name%")
                ->Where('first_lastname', 'LIKE', "%$request->first_lastname%")
                ->Where('second_lastname', 'LIKE', "%$request->second_lastname%")
                ->Where('genre', 'LIKE', "%$request->genre%");
    $request->session()->put('list', $query->get());
    $customers = $query->paginate(20);
    return view('customer.index', compact('customers'));
}

/**
 * Display a listing of the resource.
 *
 * @return \Illuminate\Http\Response
 */
public function index(Request $request)
{
    $query = Customer::select('identification', 'first_name', 'second_name', 'first_lastname', 'second_lastname', 'genre');
    $request->session()->put('list', $query->get());
    $customers = $query->paginate(20);
    return view('customer.index', compact('customers'));
}

It works perfectly, but now, I want to optimize it creating another funtion which receives the $query. Something like this:

public function displayResult(Builder $query,Request $request)
    {
        $request->session()->put('list', $query->get());
        $customers = $query->paginate(20);
        return view('customer.index', compact('customers'));
    }

The objective is to call the function from my previous methods, e.g:

public function index(Request $request)
    {
        $query = Customer::select('identification', 'first_name', 'second_name', 'first_lastname', 'second_lastname', 'genre');
        $this->displayResult($query, $request);
    }

But, my view is not displaying nothing. Am I doing something wrong? Should I use a Model instead Builder parameter? If I do so, then it's displaying this error:

Argument 1 passed to App\Http\Controllers\CustomerController::displayResult() must be an instance of App\Http\Controllers\Model, instance of Illuminate\Database\Eloquent\Builder given, called in ....on line 54 and defined

That line is exactly where I call to my new funtion. Thanks in advance.

Your displayResult() method returns the view instance, but you forgot to return it from your controller's index() method.

Replace

$this->displayResult($query, $request);

with

return $this->displayResult($query, $request);