public function blockUser($userIdentifier, $userToBlockIdentifier, $accessToken)
    {
        if ($this->apiVersionIsGreaterThanV3()) {
            if (!is_numeric($userIdentifier) || !is_numeric($userToBlockIdentifier)) {
                throw new InvalidIdentifierException('user');
            }
        }

        return $this->put(sprintf('users/%s/blocks/%s', $userIdentifier, $userToBlockIdentifier), [], $accessToken);
    }