public function headers(): array
    {
        return collect($this->response->getHeaders())->mapWithKeys(function ($v, $k) {
            return [$k => $v[0]];
        })->all();
    }
public function headers(): array
    {
        return collect($this->response->getHeaders())->mapWithKeys(function ($v, $k) {
            return [$k => $v[0]];
        })->all();
    }
public function headers ( ) : array { return collect ( $ this -> response -> getHeaders ( ) ) -> mapWithKeys ( function ( $ v , $ k ) { return [ $ k => $ v [ 0 ] ] ; } ) -> all ( ) ; }
Retrieves all header values.

@param string $header

@return array
Retrieves all header values .