Method validate does not exist - Laravel 5.4

In docs said:

$this->validate($request, [
    'email' => 'required|email',
]);

This string - works :)

Well means its no longer available in 5.4 however its available in controller

Try:

 $this->validate($request, [
    'email' => 'required|email',
 ]);

You should try this:

$validateFields = array('email' => 'required|email');

$this->validate($request, $validateFields);

OR

$this->validate($request, [
    'email' => 'required|email'
]);