*
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 7.0
 */
@GwtCompatible
public class TreeBasedTable<R, C, V> extends StandardRowSortedTable<R, C, V> {
  private final Comparator<? super C> columnComparator;

  private static final class Factory<C, V> implements Supplier<Map<C, V>>, Serializable {
    final Comparator<? super C> comparator;

 * retrieve the resource. Although URLs have many schemes (`mailto`, `file`, `ftp`), this class only
 * supports `http` and `https`. Use [java.net.URI][URI] for URLs with arbitrary schemes.
 *
 * ### Username and Password
 *
 * Username and password are either present, or the empty string `""` if absent. This class offers
 * no mechanism to differentiate empty from absent. Neither of these components are popular in

### Crear una clase `Enum` { #create-an-enum-class }

Importa `Enum` y crea una subclase que herede de `str` y de `Enum`.

Al heredar de `str`, la documentación de la API podrá saber que los valores deben ser de tipo `string` y podrá representarlos correctamente.

Luego crea atributos de clase con valores fijos, que serán los valores válidos disponibles:

```console
$ pip install python-multipart
```

Esto se debe a que **OAuth2** utiliza "form data" para enviar el `username` y `password`.

///

Ejecuta el ejemplo con:

<div class="termy">

```console
$ fastapi dev

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

## Revisa { #check-it }

* o modelo
* o modelo Pydantic
* o modelo de dados
* o modelo de banco de dados
* o modelo de formulário
* o objeto de modelo

* a classe
* a classe base
* a classe pai
* a subclasse
* a classe filha
* a classe irmã
* o método de classe

* o cabeçalho
* os cabeçalhos
* o cabeçalho de autorização
* o cabeçalho `Authorization`
* o cabeçalho encaminhado

    /** Gets the value for the entry. */
    V getValue();
  }

  /*
   * Note: the following classes have a lot of duplicate code. It sucks, but it saves a lot of
   * memory. If only Java had mixins!
   */

  /** Base class for {@link InternalEntry} implementations for strong keys. */
  abstract static class AbstractStrongKeyEntry<K, V, E extends InternalEntry<K, V, E>>
      implements InternalEntry<K, V, E> {

		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{}, clause.OrderBy{
					Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}},
				}, clause.OrderBy{
					Columns: []clause.OrderByColumn{{Column: clause.Column{Name: "name"}}},
				},
			},
			"SELECT * FROM `users` ORDER BY `users`.`id` DESC,`name`", nil,
		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{}, clause.OrderBy{

			"SELECT * FROM `users` FOR SHARE OF `users`", nil,
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsNoWait}},
			"SELECT * FROM `users` FOR UPDATE NOWAIT", nil,
		},
		{

			[]interface{}{"admin"},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.GroupBy{
				Columns: []clause.Column{{Name: "role"}},
				Having:  []clause.Expression{clause.Eq{"role", "admin"}},
			}, clause.GroupBy{
				Columns: []clause.Column{{Name: "gender"}},
				Having:  []clause.Expression{clause.Neq{"gender", "U"}},
			}},

//	}})
func (db *DB) Order(value interface{}) (tx *DB) {
	tx = db.getInstance()

	switch v := value.(type) {
	case clause.OrderBy:
		tx.Statement.AddClause(v)
	case clause.OrderByColumn:
		tx.Statement.AddClause(clause.OrderBy{
			Columns: []clause.OrderByColumn{v},
		})
	case string:
		if v != "" {
			tx.Statement.AddClause(clause.OrderBy{
				Columns: []clause.OrderByColumn{{