You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: example_test.go
    path of file: ./repos/go-cloud/secrets/hashivault
    
    the code of the file until where you have to start completion: // Copyright 2019 The Go Cl
    
func ExampleOpenKeeper() {
	// PRAGMA: This example is used on gocloud.dev; PRAGMA comments adjust how it is shown and can be ignored.
	// PRAGMA: On gocloud.dev, hide lines until the next blank line.
	ctx := context.Background()

	// Get a client to use with the Vault API.
	client, err := hashivault.Dial(ctx, &hashivault.Config{
		Token: "CLIENT_TOKEN",
		APIConfig: api.Config{
			Address: "http://127.0.0.1:8200",
		},
	})
	if err != nil {
		log.Fatal(err)
	}

	// Construct a *secrets.Keeper.
	keeper := hashivault.OpenKeeper(client, "my-key", nil)
	defer keeper.Close()
}