public function test()
{
$options = new HighchartOptions();
$options->title = new Title(['text' => 'Monthly Average Temperature', 'x' => -20]);
$options->subtitle = ['text' => 'Source: WorldClimate.com', 'x' => -20];
$this->assertEquals('{"title":{"text":"Monthly Average Temperature","x":-20},"subtitle":{"text":"Source: WorldClimate.com","x":-20}}', $options->toJson());
}
