docs: void sign(HttpRequest request, AuthConfig credentials, Date signingTime) {
          AwsSigner4Request sr = new AwsSigner4Request(region, service, request, signingTime);
          if(!request.containsHeader("X-Amz-Date")) {
              request.addHeader("X-Amz-Date", sr.getSigningDateTime());
          }
          request.addHeader("Authorization", task4(sr, credentials));
          final String securityToken = credentials.getAuth();
          if (StringUtils.isNotEmpty(securityToken)) {
              request.addHeader("X-Amz-Security-Token", securityToken);
          }
      }