*
 * <pre>
 * interface Book {...}
 * public class Books {
 *   public static Book hardcover(String title) {...}
 *   public static Book paperback(String title) {...}
 * }
 * </pre>
 *
 * <p>And all the created {@code Book} instances can be tested with:
 *
 * <pre>
 * new ClassSanityTester()
 *     .forAllPublicStaticMethods(Books.class)
 *     .thatReturn(Book.class)

 *
 * <pre>
 * interface Book {...}
 * public class Books {
 *   public static Book hardcover(String title) {...}
 *   public static Book paperback(String title) {...}
 * }
 * </pre>
 *
 * <p>And all the created {@code Book} instances can be tested with:
 *
 * <pre>
 * new ClassSanityTester()
 *     .forAllPublicStaticMethods(Books.class)
 *     .thatReturn(Book.class)

 *
 * <p>For testing against the returned instances from a static factory class, such as
 *
 * <pre>
 * interface Book {...}
 * public class Books {
 *   public static Book hardcover(String title) {...}
 *   public static Book paperback(String title) {...}
 * }
 * </pre>
 *
 * <p>please use {@link ClassSanityTester#forAllPublicStaticMethods}.
 *

				// looks like a where condition
				return []clause.Expression{clause.Expr{SQL: s, Vars: args}}
			}

			if len(args) > 0 && strings.Contains(s, "@") {
				// looks like a named query
				return []clause.Expression{clause.NamedExpr{SQL: s, Vars: args}}
			}

			if strings.Contains(strings.TrimSpace(s), " ") {
				// looks like a where condition

	if field, ok := schema.FieldsByDBName[name]; ok {
		return field
	}
	if field, ok := schema.FieldsByName[name]; ok {
		return field
	}
	return nil
}

// LookUpFieldByBindName looks for the closest field in the embedded struct.
//
//	type Struct struct {
//		Embedded struct {
//			ID string // is selected by LookUpFieldByBindName([]string{"Embedded", "ID"}, "ID")
//		}

		Name   string `gorm:"primarykey"`
		Value  string
	}

	type Book struct {
		ID     int
		Name   string
		Labels []Label
	}

	DB.Migrator().DropTable(&Label{}, &Book{})
	if err := DB.AutoMigrate(&Label{}, &Book{}); err != nil {
		t.Fatalf("failed to migrate, got %v", err)
	}

	book := Book{
		Name: "my book",
		Labels: []Label{
			{Name: "region", Value: "emea"},
		},
	}

    private final List<Thread> hooks = new ArrayList<>();

    @Override
    synchronized void addShutdownHook(Thread hook) {
      hooks.add(hook);
    }

    synchronized void shutdown() throws InterruptedException {
      for (Thread hook : hooks) {
        hook.start();
      }
      for (Thread hook : hooks) {
        hook.join();
      }
    }
  }

We are going to start from where we left in the previous chapter and increment it.

## About JWT { #about-jwt }

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

```
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
```

    rare occasion we may reject it.

**3. Review**

-   For a valid PR, reviewer (person familiar with the code/functionality)
    checks if the PR looks good or needs additional changes.
-   If all looks good, the reviewer will approve the PR.
-   If a change is needed, the contributor is requested to make the suggested
    change.
-   You make the change and submit it for the review again.

package callbacks

import (
	"fmt"
	"reflect"
	"strings"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
	"gorm.io/gorm/utils"
)

// BeforeCreate before create hooks
func BeforeCreate(db *gorm.DB) {
	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && (db.Statement.Schema.BeforeSave || db.Statement.Schema.BeforeCreate) {
		callMethod(db, func(value interface{}, tx *gorm.DB) (called bool) {