lithium\security\validation\FormSignature::key PHP Method

    public static function key(array $data)
    {
        $data += array('fields' => array(), 'locked' => array(), 'excluded' => array());
        return static::_compile(array_keys(Set::flatten($data['fields'])), $data['locked'], array_keys($data['excluded']));
    }

 public function testFormSignatureWithLabelField()
 {
     $form = new Form(array('context' => $this->context));
     $this->subject->sign($form);
     ob_start();
     $content = array($form->create(null, array('url' => 'http:///')), $form->label('foo'), $form->text('email', array('value' => 'foo@bar')), $form->end());
     $signature = ob_get_clean();
     preg_match('/value="([^"]+)"/', $signature, $match);
     list(, $signature) = $match;
     $result = $signature;
     $data = array('fields' => array('email' => 'foo@bar'));
     $expected = FormSignature::key($data);
     $this->assertEqual($expected, $result);
 }