public function getAvailableIDs(): array
    {
        if ($this->availableTz === null) {
            $this->availableTz = [];
            $available = $this->timeZoneClass->getAvailableIDs();
            foreach ($available as $id) {
                $this->availableTz[] = $id;
            }
        }

        return $this->availableTz;
    }
public function getAvailableIDs(): array
    {
        if ($this->availableTz === null) {
            $this->availableTz = [];
            $available = $this->timeZoneClass->getAvailableIDs();
            foreach ($available as $id) {
                $this->availableTz[] = $id;
            }
        }

        return $this->availableTz;
    }
public function getAvailableIDs ( ) : array { if ( $ this -> availableTz === null ) { $ this -> availableTz = [ ] ; $ available = $ this -> timeZoneClass -> getAvailableIDs ( ) ; foreach ( $ available as $ id ) { $ this -> availableTz [ ] = $ id ; } } return $ this -> availableTz ; }
Return java available timezone ids.

@return array
Return java available timezone ids .