Symfony\Component\Form\FieldGroup::isValid PHP Method

    public function isValid()
    {
        if (!parent::isValid()) {
            return false;
        }

        foreach ($this->fields as $field) {
            if (!$field->isValid()) {
                return false;
            }
        }

        return true;
    }

 public function testInvalidIfFieldIsInvalid()
 {
     $group = new FieldGroup('author');
     $group->add($this->createInvalidMockField('firstName'));
     $group->add($this->createValidMockField('lastName'));
     $group->bind(array('firstName' => 'Bernhard', 'lastName' => 'Potencier'));
     $this->assertFalse($group->isValid());
 }