/// info

Added in FastAPI 0.134.0.

///

## Use Cases { #use-cases }

You could use this if you want to stream pure strings, for example directly from the output of an **AI LLM** service.

You could also use it to stream **large binary files**, where you stream each chunk of data as you read it, without having to read it all in memory at once.

Não é **suportado** pelo Pydantic ter um modelo do Pydantic v2 com campos próprios definidos como modelos do Pydantic v1, ou vice-versa.

```mermaid
graph TB
    subgraph "❌ Not Supported"
        direction TB
        subgraph V2["Pydantic v2 Model"]
            V1Field["Pydantic v1 Model"]
        end
        subgraph V1["Pydantic v1 Model"]
            V2Field["Pydantic v2 Model"]
        end
    end

import java.util.Map;
import org.junit.Ignore;

/**
 * Basic serialization test for maps.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

import org.junit.Ignore;

/**
 * Basic reserialization test for collections.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

      because they are *always* public. -->
    <module name="RedundantModifier" />
    <!-- Checks that all java files have a package declaration and that it
      lines up with the directory structure. -->
    <module name="PackageDeclaration" />

    <!-- Checks that a local variable or a parameter does not shadow a field that is defined in the same class. -->

import org.junit.Ignore;

/**
 * Testers for {@link ListMultimap#put(Object, Object)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

import org.junit.Ignore;

/**
 * Tester for {@link Multimap#containsEntry}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultimapContainsEntryTester<K, V>

     */
    void mergeDuplicates(Model model, ModelBuildingRequest request, ModelProblemCollector problems);

    /**
     * Sets default values in the specified model that for technical reasons cannot be set directly in the Modello
     * definition.
     *
     * @param model The model in which to set the default values, must not be {@code null}.

 * looks up all implementers of this interface and calls their {@link #init(Context)} method. Note:
 * Implementors are strongly advised to inherit from {@link AbstractEventSpy} instead of directly implementing this
 * interface.
 * @since 3.0.2
 */
public interface EventSpy {
    /**
     * Context
     */
    interface Context {

        /**

                """
                List of *path operations* that will be used as OpenAPI callbacks.

                This is only for OpenAPI documentation, the callbacks won't be used
                directly.

                It will be added to the generated OpenAPI (e.g. visible at `/docs`).

                Read more about it in the