public function values(): array
    {
        return (array) \array_reduce(
            $this->parts,
            function (array $values, array $part): array {
                if ($this->isGroup($part['condition'])) {
                    /** @var EasyStatement $condition */
                    $condition = $part['condition'];
                    return \array_merge(
                        $values,
                        $condition->values()
                    );
                }
                return \array_merge($values, $part['values']);
            },
            []
        );
    }