In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

    /**
     * Indicates whether Maven should never fail the build, regardless of project result.
     *
     * @return an {@link Optional} containing true if the build should never fail, false if it should fail normally, or empty if not specified
     */
    @Nonnull
    Optional<Boolean> failNever();

    /**
     * Indicates whether Maven should resume from the last failed project in a previous build.
     *

    ), "overridden configs should be preserved"
    assert (
        '"deepLinking": true' not in response.text
    ), "overridden configs should not include the old value"
    assert (
        '"syntaxHighlight": false' not in response.text
    ), "not used parameters should not be included"
    assert (
        '"dom_id": "#swagger-ui"' in response.text
    ), "default configs should be preserved"

		t.Errorf("Hamster's preferred toy count should be 1")
	}

	if DB.Model(&hamster2).Association("OtherToy").Count() != 1 {
		t.Errorf("Hamster's other toy count should be 1")
	}

	// Query
	hamsterToy := Toy{}
	DB.Model(&hamster).Association("PreferredToy").Find(&hamsterToy)
	if hamsterToy.Name != hamster.PreferredToy.Name {
		t.Errorf("Should find has one polymorphic association")
	}

	hamsterToy = Toy{}

	if DB.Where("sdsd.zaaa = ?", "sd;;;aa").Pluck("aaa", &columns).Error == nil {
		t.Errorf("Should got error with invalid SQL")
	}

	if DB.Model(&User{}).Where("sdsd.zaaa = ?", "sd;;;aa").Pluck("aaa", &columns).Error == nil {
		t.Errorf("Should got error with invalid SQL")
	}

	if DB.Where("sdsd.zaaa = ?", "sd;;;aa").Find(&User{}).Error == nil {
		t.Errorf("Should got error with invalid SQL")
	}

	var count1, count2 int64

		t.Errorf("name should be groupby, but got %v, total should be 60, but got %v", name, total)
	}

	if err := DB.Model(&User{}).Select("name, sum(age) as total").Where("name LIKE ?", "groupby%").Group("name").Having("name = ?", "groupby1").Row().Scan(&name, &total); err != nil {
		t.Errorf("no error should happen, but got %v", err)
	}

	if name != "groupby1" || total != 660 {

    ), "not used parameters should not be included"
    assert (
        '"syntaxHighlight.theme": "obsidian"' in response.text
    ), "parameters with middle dots should be included in a JSON compatible way"
    assert (
        '"dom_id": "#swagger-ui"' in response.text
    ), "default configs should be preserved"
    assert "presets: [" in response.text, "default configs should be preserved"
    assert (

 *             but should have been.
 *
 */
@Deprecated
public interface ProjectDependenciesResolver {

    /**
     * Resolves the transitive dependencies of the specified project.
     *
     * @param project         The project whose dependencies should be resolved, must not be {@code null}.
     * @param scopesToResolve The dependency scopes that should be resolved, may be {@code null}.

	if err != nil {
		t.Fatalf("Should open db success, but got %v", err)
	}

	tx := db.Begin()
	user := *GetUser("transaction", Config{})

	if err = tx.Save(&user).Error; err != nil {
		t.Fatalf("No error should raise, but got %v", err)
	}

	if err = tx.First(&User{}, "name = ?", "transaction").Error; err != nil {
		t.Fatalf("Should find saved record, but got %v", err)
	}

* `allow_origins` - A list of origins that should be permitted to make cross-origin requests. E.g. `['https://example.org', 'https://www.example.org']`. You can use `['*']` to allow any origin.
* `allow_origin_regex` - A regex string to match against origins that should be permitted to make cross-origin requests. e.g. `'https://.*\.example\.org'`.