code: private void addPreSignInformationToRequest(SignableRequest<?> request,
              AWSCredentials credentials, AWS4SignerRequestParams signerParams,
              String timeStamp, long expirationInSeconds) {
  
          String signingCredentials = credentials.getAWSAccessKeyId() + "/"
                  + signerParams.getScope();
  
          request.addParameter(X_AMZ_ALGORITHM, AWS4_SIGNING_ALGORITHM);
          request.addParameter(X_AMZ_DATE, timeStamp);
          request.addParameter(X_AMZ_SIGNED_HEADER,
                  getSignedHeadersString(request));
          request.addParameter(X_AMZ_EXPIRES,
                  Long.toString(expirationInSeconds));
          request.addParameter(X_AMZ_CREDENTIAL, signingCredentials);
      }
docs: Includes all the signing headers as request parameters for pre-signing.