Jose\Object\JWSInterface::getSignatures PHP Method

    public function getSignatures();

 /**
  * @param \Jose\Object\JWSInterface $jws
  * @param array                     $data
  */
 private static function populatePayload(JWSInterface &$jws, array $data)
 {
     $is_encoded = null;
     foreach ($jws->getSignatures() as $signature) {
         if (null === $is_encoded) {
             $is_encoded = self::isPayloadEncoded($signature);
         }
         Assertion::eq($is_encoded, self::isPayloadEncoded($signature), 'Foreign payload encoding detected. The JWS cannot be loaded.');
     }
     if (array_key_exists('payload', $data)) {
         $payload = $data['payload'];
         $jws = $jws->withAttachedPayload();
         $jws = $jws->withEncodedPayload($payload);
         if (false !== $is_encoded) {
             $payload = Base64Url::decode($payload);
         }
         $json = json_decode($payload, true);
         if (null !== $json && !empty($payload)) {
             $payload = $json;
         }
         $jws = $jws->withPayload($payload);
     } else {
         $jws = $jws->withDetachedPayload();
     }
 }