public function toArray(array $data = [])
    {
        return array_filter(array_merge([
            'start' => $this->start,
            'range' => $this->range,
            'sort' => $this->sort,
            'sortDir' => $this->sortDirection,
            'search' => $this->search,
            'searchNotes' => $this->searchNotes,
            'condition' => $this->condition ? json_encode($this->condition) : null
        ], $data), function ($value) {
            return $value !== null;
        });
    }