13     protected $displayName;  variable in MatrixPhp\\User
21      * @param string|null $displayName
24     public function __construct(MatrixHttpApi $api, string $userId, ?string $displayName = null) {  argument
27         $this->displayName = $displayName;
45         if (!$this->displayName) {
46             $this->displayName = $this->api->getDisplayName($this->userId);
49         return $this->displayName ?: $this->userId;
55      * @param string $displayName Display Name
61     public function setDisplayName(string $displayName) {  argument
62         $this->displayName = $displayName;
64         return $this->api->setDisplayName($this->userId, $displayName);