/// tip | Consejo

Para entender las variables de entorno, puedes leer [Variables de Entorno](../environment-variables.md).

///

## Tipos y validación { #types-and-validation }

Você pode declarar uma resposta como o `Union` de dois ou mais tipos, o que significa que a resposta seria qualquer um deles.

Isso será definido no OpenAPI com `anyOf`.

Para fazer isso, use a anotação de tipo padrão do Python [`typing.Union`](https://docs.python.org/3/library/typing.html#typing.Union):

/// note | Nota

-------------

Unless the change is a trivial fix such as for a typo, it's generally best to
start by opening a new issue describing the bug or feature you're intending to
fix. Even if you think it's relatively minor, it's helpful to know what people
are working on. And as mentioned above, API changes should be discussed
thoroughly before moving to code.

Some examples of types of pull requests that are immediately helpful:

/// tip | Dica

Para entender variáveis de ambiente, você pode ler [Variáveis de Ambiente](../environment-variables.md).

///

## Tipagem e validação { #types-and-validation }

  public void testNewArrayType_upperBoundedWildcard() {
    Type wildcard = Types.subtypeOf(Number.class);
    assertEquals(Types.subtypeOf(Number[].class), Types.newArrayType(wildcard));
  }

  public void testNewArrayType_lowerBoundedWildcard() {
    Type wildcard = Types.supertypeOf(Number.class);
    assertEquals(Types.supertypeOf(Number[].class), Types.newArrayType(wildcard));
  }

  public void testNewArrayType_serializable() {

pkg go/types, method (*TypeParam) Obj() *TypeName
pkg go/types, method (*TypeParam) SetConstraint(Type)
pkg go/types, method (*TypeParam) String() string
pkg go/types, method (*TypeParam) Underlying() Type
pkg go/types, method (*TypeParamList) At(int) *TypeParam
pkg go/types, method (*TypeParamList) Len() int
pkg go/types, method (*Union) Len() int
pkg go/types, method (*Union) String() string
pkg go/types, method (*Union) Term(int) *Term

        Arrays.sort(types);
        assertEquals("document", types[0]);
        assertEquals("text", types[1]);
    }

    @Test
    public void test_getTypes_empty() {
        String[] types = fileTypeHelper.getTypes();
        assertNotNull(types);
        assertEquals(0, types.length);
    }

    @Test
    public void test_add_overwrite() {
        fileTypeHelper.add("application/pdf", "pdf");

pkg go/types, const SendOnly = 1
pkg go/types, const SendOnly ChanDir
pkg go/types, const SendRecv = 0
pkg go/types, const SendRecv ChanDir
pkg go/types, const String = 17
pkg go/types, const String BasicKind
pkg go/types, const Uint = 7
pkg go/types, const Uint BasicKind
pkg go/types, const Uint16 = 9
pkg go/types, const Uint16 BasicKind
pkg go/types, const Uint32 = 10
pkg go/types, const Uint32 BasicKind

// The mask is checked against the active subscribed types,
// and 0 will be returned if nobody is subscribed for the type(s).
func (ps *PubSub[T, M]) NumSubscribers(mask M) int32 {
	types := Mask(atomic.LoadUint64(&ps.types))
	if !types.Overlaps(Mask(mask.Mask())) {
		return 0
	}
	return atomic.LoadInt32(&ps.numSubscribers)
}

// Subscribers returns the number of current subscribers for all types.

  @CanIgnoreReturnValue
  Type[] resolveTypesInPlace(Type[] types) {
    for (int i = 0; i < types.length; i++) {
      types[i] = resolveType(types[i]);
    }
    return types;
  }

  private Type[] resolveTypes(Type[] types) {
    Type[] result = new Type[types.length];
    for (int i = 0; i < types.length; i++) {
      result[i] = resolveType(types[i]);
    }
    return result;
  }