Lcobucci\JWT\ValidationData::setIssuer PHP Method

    public function setIssuer($issuer)
    {
        if (!is_array($issuer)) {
            $issuer = [$issuer];
        }
        $this->items['iss'] = array_values(array_map('strval', $issuer));
    }

 /**
  * TokenValidator constructor.
  * @param ValidationData $validationData
  * @param Signer $signer
  * @param string $secret
  * @param array $config
  */
 public function __construct(ValidationData $validationData, Signer $signer, string $secret, array $config)
 {
     $this->validationData = $validationData;
     $this->signer = $signer;
     $this->secret = $secret;
     $this->validationData->setAudience($config['audience']);
     $this->validationData->setIssuer($config['issuer']);
     $this->validationData->setId($config['appid']);
 }