sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
	if constraint.OnDelete != "" {
		sql += " ON DELETE " + constraint.OnDelete
	}

	if constraint.OnUpdate != "" {
		sql += " ON UPDATE " + constraint.OnUpdate
	}

	foreignKeys := make([]interface{}, 0, len(constraint.ForeignKeys))
	for _, field := range constraint.ForeignKeys {
		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})

        assertNotNull(documented);
    }

    // Test annotation has Constraint meta-annotation
    public void test_annotationConstraint() {
        jakarta.validation.Constraint constraint = CronExpression.class.getAnnotation(jakarta.validation.Constraint.class);
        assertNotNull(constraint);
        Class<?>[] validators = constraint.validatedBy();
        assertEquals(1, validators.length);

    }

    // Test Constraint annotation
    public void test_constraintAnnotation() {
        final Constraint constraint = CustomSize.class.getAnnotation(Constraint.class);
        assertNotNull("Constraint annotation should be present", constraint);
        assertEquals("Validator class should be CustomSizeValidator", CustomSizeValidator.class, constraint.validatedBy()[0]);
    }

    // Test default values

    }

    // Test Constraint annotation
    public void test_constraintAnnotation() {
        final Constraint constraint = UriType.class.getAnnotation(Constraint.class);
        assertNotNull("Constraint annotation should be present", constraint);
        assertEquals("Validator class should be UriTypeValidator", UriTypeValidator.class, constraint.validatedBy()[0]);

        // Test constraint message constants
        assertEquals("{constraints.AssertFalse.message}", FessMessages.CONSTRAINTS_AssertFalse_MESSAGE);
        assertEquals("{constraints.AssertTrue.message}", FessMessages.CONSTRAINTS_AssertTrue_MESSAGE);
        assertEquals("{constraints.DecimalMax.message}", FessMessages.CONSTRAINTS_DecimalMax_MESSAGE);

	}

	expectedConstraintName := "fk_my_schema_a_very_very_very_very_very_very_very_very_l4db13eec"
	constraint := s.Relationships.Relations["Author"].ParseConstraint()

	if constraint.Name != expectedConstraintName {
		t.Fatalf(
			"expected constraint name %s, got %s",
			expectedConstraintName,
			constraint.Name,
		)
	}
}

type InfoRelation struct {
	ID    int
	Code  string

	replaceDirective = "REPLACE"
	accessDirective  = "ACCESS"
)

// Parses location constraint from the incoming reader.
func parseLocationConstraint(r *http.Request) (location string, s3Error APIErrorCode) {
	// If the request has no body with content-length set to 0,
	// we do not have to validate location constraint. Bucket will
	// be created at default region.
	locationConstraint := createBucketLocationConfiguration{}

			t.Fatalf("failed to drop constraint %v, got error %v", name, err)
		}

		if DB.Migrator().HasConstraint(&User{}, name) {
			t.Fatalf("constraint %v should been deleted", name)
		}

		if err := DB.Migrator().CreateConstraint(&User{}, name); err != nil {
			t.Fatalf("failed to create constraint %v, got error %v", name, err)
		}

Then I contributed to it, to make it fully compliant with JSON Schema, to support different ways to define constraint declarations, and to improve editor support (type checks, autocompletion) based on the tests in several editors.

		payload, err := io.ReadAll(io.LimitReader(r.Body, maxLocationConstraintSize))
		if err != nil {
			authZLogIf(ctx, err, logger.ErrorKind)
			return ErrMalformedXML
		}

		// Populate payload to extract location constraint.
		r.Body = io.NopCloser(bytes.NewReader(payload))
		region, s3Err = parseLocationConstraint(r)
		if s3Err != ErrNone {
			return s3Err
		}

		// Populate payload again to handle it in HTTP handler.