public function testAddCheckbox()
{
$builder = new FieldsBuilder('fields');
$builder->addCheckbox('colors')->addChoice('red')->addChoice('blue')->addChoice('green');
$expectedConfig = ['fields' => [['name' => 'colors', 'type' => 'checkbox', 'choices' => ['red' => 'red', 'blue' => 'blue', 'green' => 'green']]]];
$this->assertArraySubset($expectedConfig, $builder->build());
}