$this->cost] ); } public function isPasswordValid(UserInterface $user, string $plainPassword): bool { return password_verify( $plainPassword, $user->getPassword() ); } public function setCost(int $cost): void { if ($cost < 4 || $cost > 12) { throw new \InvalidArgumentException('Cost must be in the range of 4-31.'); } $this->cost = $cost; } }