For testing purposes, here is [how to create self-signed certificates](https://github.com/minio/minio/tree/master/docs/tls#3-generate-self-signed-certificates).

## 2. Create Kubernetes secret

[Kubernetes secrets](https://kubernetes.io/docs/concepts/configuration/secret) are intended to hold sensitive information.

 *    they've confirmed that the owner of the private key is also the owner of the certificate's
 *    other properties.
 *
 * Certificates are signed by other certificates and a sequence of them is called a certificate
 * chain. The chain terminates in a self-signed "root" certificate. Signing certificates in the
 * middle of the chain are called "intermediates". Organizations that offer certificate signing are

	hash.Write(data)
	return hash.Sum(nil)
}

// extractSignedHeaders extract signed headers from Authorization header
func extractSignedHeaders(signedHeaders []string, r *http.Request) (http.Header, APIErrorCode) {
	reqHeaders := r.Header
	reqQueries := r.Form
	// find whether "host" is part of list of signed headers.
	// if not return ErrUnsignedHeaders. "host" is mandatory.

    ): Builder = commonMethod(method, body)

    /**
     * Attaches [tag] to the request using [T] as a key. Tags can be read from a request using
     * [Request.tag]. Use null to remove any existing tag assigned for [T].
     *
     * Use this API to attach timing, debugging, or other application data to a request so that
     * you may read it in interceptors, event listeners, or callbacks.
     */
    @JvmName("reifiedTag")

    return this
  }

  /** Returns true if a value has been assigned for the setting `id`. */
  fun isSet(id: Int): Boolean {
    val bit = 1 shl id
    return set and bit != 0
  }

  /** Returns the value for the setting `id`, or 0 if unset. */
  operator fun get(id: Int): Int = values[id]

  /** Returns the number of settings that have values assigned. */
  fun size(): Int = Integer.bitCount(set)

	}

	// Since the list of signed headers value contained `expect`, the default value of `100-continue` will be added to extracted signed headers.
	if extractedExpect != expectedExpect {
		t.Errorf("expect header incorrect value: expected `%s`, got `%s`", expectedExpect, extractedExpect)
	}

	// case where the headers don't contain the one of the signed header in the signed headers list.

		},
		CustomSerializerString: "world",
	}

	// first time insert record
	out := SerializerStruct{}
	if err := DB.Assign(data).FirstOrCreate(&out).Error; err != nil {
		t.Fatalf("failed to FirstOrCreate Assigned data, got error %v", err)
	}

	var result SerializerStruct
	if err := DB.First(&result, out.ID).Error; err != nil {
		t.Fatalf("failed to query data, got error %v", err)
	}
	AssertEqual(t, result, out)

 * signed versions of methods for which signedness is an issue.
 *
 * <p>In addition, this class provides several static methods for converting a {@code long} to a
 * {@code String} and a {@code String} to a {@code long} that treat the {@code long} as an unsigned
 * number.
 *
 * <p>Users of these utilities must be <i>extremely careful</i> not to mix up signed and unsigned

  // `scope-hostname.io/name`.
  // If empty, it will be defaulted:
  //  1. If it's a kubelet client certificate, it is assigned
  //     "kubernetes.io/kube-apiserver-client-kubelet".
  //  2. If it's a kubelet serving certificate, it is assigned
  //     "kubernetes.io/kubelet-serving".
  //  3. Otherwise, it is assigned "kubernetes.io/legacy-unknown".
  // Distribution of trust for signers happens out of band.

    call: Call,
  ) {}

  /**
   * Invoked when a connection is released as no longer required.
   */
  open fun connectionClosed(connection: Connection) {}

  /**
   * Invoked when a call is assigned a particular connection.
   */
  open fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {}

  /**
   * Invoked when a call no longer uses a connection.
   */