AdamWathan\Form\Elements\Select::addOption PHP Method

    public function addOption($value, $label)
    {
        $this->options[$value] = $label;
        return $this;
    }

 public function testCanAddOption()
 {
     $select = new Select('color', array('red' => 'Red'));
     $select->addOption('blue', 'Blue');
     $expected = '<select name="color"><option value="red">Red</option><option value="blue">Blue</option></select>';
     $result = $select->render();
     $this->assertEquals($expected, $result);
     $select = new Select('fruit', array('apple' => 'Granny Smith'));
     $select->addOption('berry', 'Blueberry');
     $expected = '<select name="fruit"><option value="apple">Granny Smith</option><option value="berry">Blueberry</option></select>';
     $result = $select->render();
     $this->assertEquals($expected, $result);
 }