protected function isValid($value)
    {
        if (is_null($value)) {
            return;
        } elseif ($value) {
            $context = [$value];
        } else {
            $context = [];
        }

        $q = new FlowQuery($context);

        if ($q->is('[instanceof ' . $this->options['type'] . ']')) {
            return;
        }

        $this->addError('The value is expected to satisfy the %s flowQuery condition.', 1515144113, [
            $this->options['type']
        ]);
    }