Encore\Admin\Form::prepare PHP Method

    protected function prepare($data = [], Closure $callback = null)
    {
        $this->inputs = $data;
        if ($callback instanceof Closure) {
            $callback($this);
        }
        $this->updates = array_filter($this->inputs, function ($val) {
            return is_string($val) or $val instanceof UploadedFile;
        });
        $this->relations = array_filter($this->inputs, 'is_array');
    }