<AssumedRoleUser>
      <Arn/>
      <AssumeRoleId/>
    </AssumedRoleUser>
    <Credentials>
      <AccessKeyId>Y4RJU1RNFGK48LGO9I2S</AccessKeyId>
      <SecretAccessKey>sYLRKS1Z7hSjluf6gEbb9066hnx315wHTiACPAjg</SecretAccessKey>
      <Expiration>2019-08-08T20:26:12Z</Expiration>

      /* Amazon S3: */
      // MinioClient minioClient =
      //     MinioClient.builder()
      //         .endpoint("https://s3.amazonaws.com")
      //         .credentials("YOUR-ACCESSKEY", "YOUR-SECRETACCESSKEY")
      //         .build();

      // Enable versioning on 'my-bucketname'.
      minioClient.enableVersioning(EnableVersioningArgs.builder().bucket("my-bucketname").build());

	}
}

// postPresignSignatureV4 - presigned signature for PostPolicy requests.
func postPresignSignatureV4(policyBase64 string, t time.Time, secretAccessKey, location string) string {
	// Get signining key.
	signingkey := getSigningKey(secretAccessKey, t, location, "s3")
	// Calculate signature.
	signature := getSignature(signingkey, policyBase64)
	return signature
}

    <AssumedRoleUser>
      <Arn/>
      <AssumeRoleId/>
    </AssumedRoleUser>
    <Credentials>
      <AccessKeyId>Y4RJU1RNFGK48LGO9I2S</AccessKeyId>
      <SecretAccessKey>sYLRKS1Z7hSjluf6gEbb9066hnx315wHTiACPAjg</SecretAccessKey>
      <Expiration>2019-08-08T20:26:12Z</Expiration>

)

// Credentials holds access and secret keys.
type Credentials struct {
	AccessKey    string                 `xml:"AccessKeyId" json:"accessKey,omitempty" yaml:"accessKey"`
	SecretKey    string                 `xml:"SecretAccessKey" json:"secretKey,omitempty" yaml:"secretKey"`
	SessionToken string                 `xml:"SessionToken" json:"sessionToken,omitempty" yaml:"sessionToken"`