```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

Using `Optional[str]` instead of just `str` will let the editor help you detect errors where you could be assuming that a value is always a `str`, when it could actually be `None` too.

`Optional[Something]` is actually a shortcut for `Union[Something, None]`, they are equivalent.

	if idxName != "idx_public_table_name" {
		t.Errorf("invalid index name generated, got %v", idxName)
	}

	chkName := ns.CheckerName("public.table", "name")
	if chkName != "chk_public_table_name" {
		t.Errorf("invalid checker name generated, got %v", chkName)
	}

	joinTable := ns.JoinTableName("user_languages")
	if joinTable != "public.user_languages" {
		t.Errorf("invalid join table generated, got %v", joinTable)
	}

		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")
	}

     * Constructor for SuggestDeleteResponse.
     * @param errors A list of Throwables representing errors.
     * @param took The time taken for the operation in milliseconds.
     */
    protected SuggestDeleteResponse(final List<Throwable> errors, final long took) {
        this.took = took;
        if (errors != null && !errors.isEmpty()) {
            this.errors.addAll(errors);
        }
    }

    /**

Esto también significa que si algo cambió será **reflejado** automáticamente en el código del cliente. Y si haces **build** del cliente, te dará error si tienes algún **desajuste** en los datos utilizados.

      raising an error and quitting.

  Returns:
    [String] The value of var_name after querying for input.

  Raises:
    UserInputError: if a query has been attempted n_ask_attempts times without
      success, assume that the user has made a scripting error, and will
      continue to provide invalid input. Raise the error to avoid infinitely
      looping.
  """

			if r.Name != relation.Name {
				t.Errorf("schema %v relation name expects %v, but got %v", s, r.Name, relation.Name)
			}

			if r.Type != relation.Type {
				t.Errorf("schema %v relation name expects %v, but got %v", s, r.Type, relation.Type)
			}

			if r.Schema.Name != relation.Schema {
				t.Errorf("schema %v relation's schema expects %v, but got %v", s, relation.Schema, r.Schema.Name)

* Sort resources in quota errors to avoid duplicate events ([#25161](https://github.com/kubernetes/kubernetes/pull/25161), [@derekwaynecarr](https://github.com/derekwaynecarr))
* Display line number on JSON errors ([#25038](https://github.com/kubernetes/kubernetes/pull/25038), [@mfojtik](https://github.com/mfojtik))

* Correctly handle transient connection reset errors on GET requests from client library. ([#58520](https://github.com/kubernetes/kubernetes/pull/58520), [@porridge](https://github.com/porridge))

[`x509usepolicies` setting](/pkg/crypto/x509/#CreateCertificate).


### Go 1.21

Go 1.21 made it a run-time error to call `panic` with a nil interface value,
controlled by the [`panicnil` setting](/pkg/builtin/#panic).

Go 1.21 made it an error for html/template actions to appear inside of an ECMAScript 6
template literal, controlled by the