How to use the @kosko/generate.PrintFormat.YAML function in @kosko/generate

builder(argv) {
    /* istanbul ignore next */
    return generateBuilder(argv)
      .option("output", {
        type: "string",
        describe: "Output format",
        default: PrintFormat.YAML,
        choices: Object.keys(PrintFormat).map(key => (PrintFormat as any)[key]),
        alias: "o"
      })
      .option("validate", {
        type: "boolean",
        describe: "Validate components",
        default: true
      })
      .example("$0 generate", "Generate manifests")
      .example("$0 generate foo bar", "Specify components")
      .example("$0 generate foo_*", "Use glob pattern")
      .example("$0 generate --env foo", "Set environment")
      .example("$0 generate -r ts-node/register", "Require external modules");
  },
  async handler(args) {

test("should call print with given format", () => {
      expect(print).toHaveBeenCalledWith(result, {
        format: PrintFormat.YAML,
        writer: process.stdout
      });
    });
  });

beforeAll(() => {
      args.output = PrintFormat.YAML;
    });