public function setSessionIndex(string $sessionIndex = null) : void
    {
        if (is_null($sessionIndex)) {
            $this->sessionIndexes = [];
        } else {
            $this->sessionIndexes = [$sessionIndex];
        }
    }
public function setSessionIndex(string $sessionIndex = null) : void
    {
        if (is_null($sessionIndex)) {
            $this->sessionIndexes = [];
        } else {
            $this->sessionIndexes = [$sessionIndex];
        }
    }
public function setSessionIndex ( string $ sessionIndex = null ) : void { if ( is_null ( $ sessionIndex ) ) { $ this -> sessionIndexes = [ ] ; } else { $ this -> sessionIndexes = [ $ sessionIndex ] ; } }
Set the sesion index of the session that should be terminated.

@param string|null $sessionIndex The sesion index of the session that should be terminated.
@return void
Set the sesion index of the session that should be terminated .